is *r~T~1~-il~ E
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DOE/ER-0485P

UC-402

Summaries of FY 1990

Engineering Research

U.S. Department of Energy

Office of Energy Research

Office of Basic Energy Sciences

Division of Engineering and Geosciences

Washington, D.C. 20585
Foreword

This report documents the BES Engineering Research program for fiscal year 1990; it

provides a summary for each of the program projects in addition to a brief program

overview. The report is intended to provide staff of Congressional committees, other

executive departments, and other DOE offices with substantive program information so

as to facilitate governmental overview and coordination of Federal research programs.

Of equal importance, its availability facilitates communication of program information

to interested research engineers and scientists. The organizational chart for the DOE

Office of Energy Research (OER) on the next page delineates the six Divisions within

the OER Office of Basic Energy Sciences (BES). Each BES Division administers

basic, mission oriented research programs in the area indicated by its title. The BES

Engineering Research program is one such program; it is administered by the

Engineering and Geosciences Division of BES. Dr. Oscar P. Manley is technical

manager of the Engineering Research program; inquiries concerning the program may

be addressed to him, in writing or by phone at (301) 353-5822.

In preparing this report we asked the principal investigators to submit summaries for

their projects that were specifically applicable to fiscal year 1990. The summaries

received have been edited if necessary, but the press for timely publication made it

impractical to have the investigators review and approve the summaries prior to

publication. For more information about a given project, it is suggested that the

investigators be contacted directly.
Engineering Research Program

within DOE

Secretary of Energy

Deputy Secretary

Under Secretary

Assistant Secretaries Office of Energy Research * Federal Energy

* Nuclear Energy Regulatory Commission

* Conservation and Renewable * Economic Regulatory

* Fossil Commission

* Defense * Energy Information

* Environmental Administration

* International Affair etc.

* Program Analys siic Energy Sciences Management

* Magnetic Fusion . * Special Programs

* High Energy and Nuclear Physics · Scientific Computing

* Health and Environmental Research

* Field Operations

* Material Sciences Division Engineering and * Advanced Energy Projects

* Chemical Sciences Division Geosciences Division * Biological Energy

Research

Ensineering

Research Program
Introduction

The individual project summaries follow the program overview. The summaries are

ordered alphabetically by name of institution and so the table of contents lists all the

institutions at which projects were sponsored in fiscal year 1990.

The projects are numbered sequentially for individual identification in the indexes. Each

project entry begins with an institutional-departmental heading. The project number

precedes the capitalized project title. The names of investigators are listed immediately

below the title. The funding level for fiscal year 1990 appears to the right of title; it is

followed by the budget activity number (e.g.,01A). These numbers categorize the projects

for budgetary purposes and the categories are described in the budget number index. The

year in which either the project began or was renewed and the anticipated duration in years

are indicated respectively by the first two and last digits of the sequence directly below the

budget activity number (e.g., 88-). The summary description of the project completes the

entry.
Program Review

BES Engineering Research

The BES Engineering Research Program is one of the component research programs which

collectively constitute the DOE Basic Energy Sciences program. The DOE Basic Energy

Sciences program supports energy related research in the physical and biological sciences,

and in engineering. The chief purpose of the DOE Basic Energy Sciences program is to

provide the fundamental scientific base on which identification and development of future,

national energy options will depend. The major product of the program becomes part of

the body of data and knowledge upon which the applied energy technologies are founded;

the product is knowledge relevant to energy exploration, production, conversion and use.

The BES Engineering Research Program was started in 1979 to help resolve the numerous

serious engineering issues arising from efforts to meet U.S. energy needs. The program

supports fundamental research on broad, generic topics in energy related engineering topics

not as narrowly scoped as those addressed by the shorter term engineering research projects

sponsored by the various DOE technology programs. Special emphasis is placed on

projects which, if successfully concluded, will benefit more than one energy technology.

During the first year several workshops were sponsored for the purpose of identifying

energy related engineering research needs and initial priorities. Representatives from

industry, academic institutions, national laboratories, and leading members of professional

organizations (Engineering Societies Commission of Energy, American Society of

Mechanical Engineers, Society of Automotive Engineers, and Joint Automation and Control

Committee) participated in the workshops. In addition to the participants in the workshops,

staff representatives from the DOE technology programs and other leading U.S. energy

engineering experts made significant contributions to the setting of program priorities.

There resulted from this process a strong confirmation of the need for a long range,

fundamental engineering research program with two major goals. The broad goals that

were established by this process for the BES Engineering Research Program are:

1) To extend the body of knowledge underlying current engineering practice so as to

create new options for enhancing energy savings and production, for prolonging useful

equipment life, and for reducing costs without degradation of industrial production and

performance quality; and

2) To broaden the technical and conceptual base for solving future engineering problems

in the energy technologies.
In this process, it was further established that to achieve these goals, the BES Engineering

Research Program should address the following topics identified as essential to the progress

of many energy technologies:

1) Advanced Industrial Technology: improvement of energy conversion and utilization,

opening new technological possibilities, and improvement of energy systems.

2) Fluid Dynamics and Thermal Processes: broadening of understanding of heat transfer

in nonsteady flows, methodology for reducing vibrations and noise in heat exchangers, and

engineering aspects of combustion.

3) Solid Mechanics: continuum mechanics, fracture mechanics, thermomechanical

behavior in severe environments, aging & lifetime reliability of structures.

4) Dynamics and Control of Processes and Systems: development and use of information

describing system behavior (system models), performance criteria, and theories of control

optimization to achieve the best possible system performance subject to known constraints.

A Scoping Workshop held in December, 1985 confirmed the continued needs for research

in these topical areas. Because of budgetary limitations, the implemented BES Engineering

Research Program is somewhat less broad than the program envisioned above. At present,

equal emphasis is being placed in three carefully selected, high priority research areas;

namely,

1) Mechanical Sciences including Fluid Mechanics (Multiphase flow and turbulence) heat

transfer, and solid mechanics (continuum mechanics and fracture mechanics).

2) System Sciences including process control and instrumentation.

3) Engineering Analysis including nonlinear dynamics, data bases for thermophysical

properties of fluids, and modeling of combustion processes for engineering application.

These areas contain the most critical elements of the four topics enumerated above; as such

they are of importance to energy technologies both in the short and long term, and

therefore of immediate programmatic interest. It should be noted that other areas of basic

research important to engineering are monitored elsewhere in BES. ,For instance,

separation sciences and research on thermophysical properties are among the

responsibilities of the Chemical Sciences Division, while microscopic aspects of fracture

mechanics are in the domain of the Material Sciences Division. As resources permit, other

high priority areas are being added to the Engineering Research Program. Thus as a result

of previous growth in the program budget an important development took place in the

Engineering Research Program: two major concentrations of research were initiated.
First, a new program was organized at Oak Ridge National Lab dealing with intelligent

machines in unstructured environment. Some resources are available for coordinated, more

narrowly focussed related, high quality research at universities and other research centers.

All such activities are supported and administered directly by the Engineering Research

Program, but some coordination of efforts with the ORNL program may prove useful.

The research opportunities in this area of interest to the DOE Engineering Research

Program have been identified in a workshop held in November, 1983. Proceedings of the

workshop entitled "Research Needs in Intelligent Machines" are available from the Center

for Engineering Advanced Systems Research, Oak Ridge National Lab, Post Office Box

X, Oak Ridge, TN, 37830.

Secondly in FY 1985 there started a collaborative research effort between MIT and Idaho

National Engineering Lab. At present, the collaboration is in three distinct areas: Plasma

Process Engineering, Automated Welding, and Fracture Mechanics. Collateral, high quality

research efforts at other institutions are'supported by the Engineering Research Program.

In the expectation of a future modest growth of thisProgram, two International Workshops

on Two Phase Flow Fundamental were held one in September 1985 and the other in march

1987. The meetings were used to identify basic research needs in the field of two phase

flow and heat transfer; summary reports of the workshops are available from the Program

Office. The proceedings of the two workshops have been published as volumes in the

series "Advances in Heat and Mass Transfer" (Hemisphere Publishing Company)

Two additional workshops were held during 1988. The first dealt with possible research

opportunities in the field of novel devices using the new high temperature superconductors.

The second addressed research needs for bioprocessing of fuels and energy related wastes.

Reports of both workshops have been published.

It should be mentioned too, that some very limited support is available for research on

large scale systems. A report of a Workshop on Needs, Opportunities, and Options in this

field is available from Professor G.L. Thompson, Graduate School of Industrial

Administration, Carnegie-Mellon University, Pittsburgh, PA 15213.

Research projects sponsored by the BES Engineering Research Program are currently

underway at universities, private sector laboratories, and DOE national laboratories. In

fiscal year 1990 the available program operating funds available amounted to about $14.7

million. The distribution of these funds among various institutions and by topical area is

illustrated on the next page. Project funding levels are mostly in the range of $50,000 to

$150,000 per year. Typical duration of a project is three to four years, with some projects

expected to last as long as ten years or more. The BES Engineering Research projects

stem almost without exception from proposals for competitive grants. Proposals which

anticipate definite results in less than two years are usually referred to the appropriate DOE

technology program for consideration. All those interested in submitting a proposal are
encouraged to discuss their ideas with the technical program manager prior to submission

of a formal proposal. Such discussion helps to establish whether or not a potential project

has a reasonable chance of being funded. The primary considerations for possible support

are the technical quality of the proposal and the professional standing of the principal

investigators and staff. An effort is made to attract first rate, younger research engineers

and energy oriented applied scientists. A high technical caliber of research is maintained

by requiring that the projects supported have potential for a significant contribution to

energy related engineering science, or for an initial contribution to a new energy relevant

technology. Sponsored projects are selected primarily for their relevance to DOE mission

requirements; the contribution to energy related higher eduction is an important but

secondary consideration. Thus projects sponsored at universities are essentially limited to

advanced studies both theoretical and experimental usually performed by faculty members,

staff research scientists, and doctoral candidates.
ENGINEERING RESEARCH PROGRAM

FY '90 BUDGET ($000's)

BY INSTITUTIONAL TYPE

NATIONAL UNIVERSITIES

LABORATORIES 58%

32% $8596

$4638 (87. PROJECTS)

(18 PROJECTS)

OTHER

10%

$1452

(10 PROJECTS)

ENGINEERING RESEARCH PROGRAM

FY '90 BUDGET

BY TECHNICAL AREAS

($000 s) % NUMBER OF PROJECTS

MECHANICAL SCIENCES 4357 30 43

SYSTEMS SCIENCES 4993 34 25

ENGINEERING ANALYSIS 5336 36 47
Table of Contents

University of Alabama ............................ 1

Ames Laboratory .............................. 1

Argonne National Laboratory ...................... 2

Arizona State University ......................... 2

Batelle ..................................... 3

Boston University ............................. 3

Brown University ............................. 4

University Of California, Berkeley .................. 4

University Of California, Los Angeles ................ 5

University Of California, San Diego ................. 7

University Of California, Santa Barbara ......... ,..... 10

Carnegie Mellon University ....................... 11

University Of Chicago .......................... 12

Clarkson University ............................ 13

University Of Connecticut ........................ 14

Cornell University ............................. 14

Dartmouth College ............................. 15

Duke University .................. ............. 15

Engineering Science Software, Inc .................. 16

University Of Houston .......................... 16

Idaho National Engineering Laboratory ............... 17

University Of Illinois ........................... 21

University Of Illinois At Chicago ................... 22

Jet Propulsion Laboratory ........................ 22

Johns Hopkins University : .................... 23

Robert H. Kraichnan, Inc. ........................ 23

Lawrence Berkeley Laboratory ..................... 24

Lovelace Medical Foundation ...................... 25

University Of Maryland ......................... 25

University Of Massachusetts ................. :.... 28

Massachusetts Institute Of Technology ............. ,. 29

Los Alamos National Laboratory ................... 34

Sandia National Laboratories ...................... 34

University Of Minnesota ......................... 35

National Institute Of Standards And Technology ......... 36

The City University Of New York, The City College ..... 37

North Carolina State University .......... .. ..... 40

Northwestern University ....................... 40

University Of Notre Dame ........................ 42
Table of Contents (continued)

Oak Rifdge National Laboratory .................... 42

Ohio State University .................... .... 43

University Of Pennsylvania ....................... 44

Physical Optics Corporation ....................... 44

Physical Sciences Inc ................ .. ........ 45

Princeton University ............................ 45

Purdue University .... ..................... 46

Rensselaer Polytechnic Institute ..................... 47

University Of Rochester ................ ...... 49

The Rockefeller University ....................... 50

Sandia National Laboratories ...................... 50

Stanford University .......................... 51

Stevens Institute Of Technology ................... . 54

University Of Texas At Austin ..................... 55

Tufts University ............................. 56

United Technologies Research Center ............... 57

Washington University ..... ................... 57

Washington State University ...................... 58

University Of Wisconsin ......................... 58
University of Alabama domains of basic parameters are indicated in

Department of Mathematics $44,547 which the instability cannot break up the flow.

Tuscaloosa, AL 35487 -01-C The finite but small oscillations of the interface

90-1 - can have the character of either deterministic

Linear and Nonlinear Stability Topics In chaos or else a nonlinear propagating wave.

Physico-Chemical Hydrodynamics

AL Frenkel Ames Laboratory

The objective of this project is to advance the Institute for Physical Research $254,388

understanding of instabilities of several fluid and Technology 03-B

systems relevant to energy engineering sciences. Ames, IA 50011-3020 88-3

Some problems, approaches to their solution,

and results follow. New Ultrasonic Imaging and Measurement

Techniques for NDE

For the problem of coherent structures and the D.O. Thompson, D.IK Hsu

inverse energy cascade in turbulent flows, both

statistical ensembles and deterministic periodic The objective of this project is to develop new

flows are considered. knowledge and techniques for the nondestructive

detection and characterization of flaws in

It is found that an isotropic turbulent flow is materials and structures and the measurement of

stable to the mean-flow perturbations. This selected material properties that are important in

suggests that some statistical anisotropy is obtaining materials reliability and structural

necessary for the growth of the coherent integrity. In order to achieve this goal, efforts are

structures. made to develop new and novel ultrasonic NDE

capabilities and to characterize emerging

The same techniques, based on mathematical materials. Use is made of a multiviewing system

insights into the properties of functionals of previously developed in this work and

Gaussian processes, yields a new description of quantitative elastic wave theories in the

the diffusion of a passive scalar - such as the interpretation of results as well as microfocus

temperature - in a turbulent flow. radiography and eddy current techniques. Three

major thrusts are being pursued:

For a deterministic unidirectional flow with a

sinusoidal profile of velocity, it is shown 1) Nondestructive material characterization

rigorously - by using continued fractions - that methods are being explored for high transition

some perturbations which do not have the same temperature superconducting ceramics using

periodicity as the basic flow, can nevertheless three types of probing fields: x-ray, eddy

grow. The much more complicated case when current, and ultrasound. Efforts are aimed at

the flow is, in addition, sinusoidal in time is nondestructive measurements that can be used

reduced to an infinite algebraic eigenvalue to monitor material processing techniques.

problem. Its Galerkin approximation results are

not restricted to large scales, in contrast to 2) Novel techniques have been developed that

earlier results. An exact solution of a allow the fabrication of ultrasonic transducers

generalized Orr-Sommerfeld equation in the that have fundamentally important wave

inviscid case is found and compared to the propagation properties of engineering

Galerkin-based results. significance. Two such transducers, a Gaussian

beam transducer and a Bessel beam transducer,

For the core-annular flow - important in the have been developed. The Gaussian beam is

lubricated pipelining of heavy oils - a new field and the Bessel beam can potentially lead to

nonlinear interface equation is derived. It reflects diffraction-free elastic waves.

the dynamics of the core in addition to the

dynamics of the lubricating film. Several

Engineering Research 1 1990
3) New techniques for ultrasonic computed Arizona State University tomographic imaging (reconstruction) are being Mechanical & Aerospace Eng. $53,000

explored that utilize elastic wave scattering Tempe, AZ 85287 01-A

models and the multiviewing instrumentation. 88-4

This is an important innovation in that images so Continuum Damage Mechanics II

obtained are expected to be free of distortions D. Kracinovic

due to effects of material anisotropy and complex

surfaces encountered in some current imaging The efforts in the first two years of this research

techniques. program were focused on the development of a

micromechanically inspired continuum damage

mechanics model. Specifically, the objective was

Argonne National Laboratory to formulate a rigorous micro-to-macro transition

Materials and Components Technology along with the conditions which must be satisfied

Division $127,194 for this transition to be valid. For example, it was

Argonne, IL 60439 01-A demonstrated that the change in elastic

87-3 compliance is a proper choice for the

Bounds on Dynamic Plastic Deformation thermodynamic macro-flux since it represents an

C.KI Youngdahl orientation weighted volume average of microfluxes. The corresponding affinity is the energy

Analytical studies are being performed to develop release rate integrated along the crack perimeter

load correlation parameters which can be used and averaged across its surface. The macroin approximating or bounding the dynamic plastic potential is subsequently determined as an inner

deformation of structures. In many applications envelope of the micro-potential. The

where the load is transmitted to the structure corresponding damage surface is a convex

through a fluid, details of the load history and piecewise smooth hypersurface possessing the

spatial distribution significantly affect the final normality property. The ensuing computations

plastic deformation. The objective of the clearly indicate the simplicity and accuracy of the

program is to devise load correlation parameters proposed model in several illustrative examples.

based on various weighted integrals of the

time-space load distributions which can be used The micro-to-macro transition is, however,

to characterize the effects of the load without proven to be valid only as long as the application

resorting to detailed numerical analysis. These of the effective continua theories is justified. In

load correlation parameters have three important other words, the macro flow potential cannot be

uses: to perform design and safety analyses of proven to exist when the influence of the direct

structures over a wide range of design variables interaction of micro-defects on the deformation

and loadings; to validate computer programs becomes significant.

which have a nonlinear dynamic plasticity

capability; and to correlate experimental One of the most important aspects of the

simulations with actual or predicted events. The analyses of brittle deformation processes is the

dynamic plastic deformation of some basic determination of failure which is, obviously,

structural configurations will be analyzed for associated with a critical microcrack density.

loadings which vary both in magnitude and However, the analytical modeling of the soregion of application'with time. Load correlation called cooperative phenomena, characterized in

parameters will be hypothesized and their the considered case by a disorder of the material

usefulness in predicting final plastic deformation microstructure and the interaction of many

will be determined. The analyses will be based defects of random geometry, distribution and

initially on a rigid, perfectly plastic material model orientation represents a serious problem. This

and small deformation response, but will be class of problems, being inherently

extended to include strain hardening, an initial nondeterministic in nature, is seldom if ever

elastic response period, and large deformation addressed in continuum mechanics. A promising

interactions. strategy, to be explored in the continuation of this

Engineering Research 2 1990
research program, is to consider the application load creep with thermal gradients. Analytical

of the so-called percolation theory. One of the techniques for predicting crack growth and failure

two main problems is to make a transition under these conditions will be critically examined

between the lattice and continuum percolation by direct comparison to experimental data

theory and recover the damage micro-flux developed here. Appropriate constitutive

(Budiansky-O'Connell variable) and enable relations will be utilized in a finite element

mapping between the two models. The other approach to determine parameters which

problem is that the disorder is introduced into the characterize time and history dependent damage

percolation model traditionally by a bimodal during crack nucleation and growth. It is hoped

distribution which might be to restrictive for real that methods developed may then be used by

materials having a richer hierarchy of strengths practicing engineers to enhance the life of high

on the micro-scale. Nevertheless, it is felt that temperature structural systems during the design

the percolation theory offers a viable framework phase. This is the first year of this research

for the studies of the brittle deformation effort.

processes in the vicinity of the percolation

thresholds (which are different that those

associated with transport phenomena). The Boston University

application of the percolation theory is important Department of Chemistry $66,650

since it enables studies of estimates which the Boston MA 02215 06-C

local fluctuations of stresses (hot-spots) and 89-3

strengths (weak-links) have on the failure of the Transport In Porous/Disordered Materials

material.T. Keyes T. Keyes

The aim of this project is the construction of

Battelle theories of the transport processes-diffusion,

Mechanics Department $90,083 fluid flow, electromagnetic wave propagation, etc.

Columbus, OH 43201-2693 01-A -in materials where strong interactions or

90-3 disorder cause a near stoppage of the transport.

An Investigation of the Effects of History Of special interest are materials with percolation

Dependent Damage In Time Dependent thresholds, where the disorder blocks transport

Fracture Mechanics altogether, and systems near a glass transition.

F.W. Brust The research is broadly based and a wide range

of theoretical and computational techniques are

The demands for structural systems to perform employed. Progress along three fronts was

reliably under severe operating conditions made in the past year.

continues to increase. Modern energy

production facilities experience degradation and Harmonic normal mode analysis is routinely

damage because they operate in a severe high- applied to stable solids, but is not normally

temperature environment where time dependent considered useful for fluids. We have developed

straining and damage may lead to structural a new method for fluid dynamics, based upon

failures. The goal of this research is to study the normal mode analysis, in which transport is

high temperature damage and failure processes governed by the unstable modes of the system.

and to further develop a method for predicting The method worked extremely well for

this behavior in an effort to increase structural supercooled liquids and is now being applied to

life. In particular, we focus on time dependent suspensions of spheres.

damage which occurs under history-dependent

loading conditions, i.e. transient conditions. Glass ceramics are composed of irregular

crystallites in a glassy matrix. The propagation

The types of time dependent (creep) damage of light through these disordered materials was

considered in this program include: sustained studied. The structure of the crystallites was

load creep, variable load creep, and variable related to the properties of the scattered light in

Engineering Research 3 1990
a completely new scheme which requires the The present task is to examine the qualitative

intensity statistics, but no knowledge of optical effects of nonequilibrium on the general flow

properties. characteristics and on critical flow. In particular,

a combined numerical and analytic study has

High intensity light will break chemical bonds and re-interpreted the well-known Moby Dick

cut material. A fairly comprehensive model of experiments suggesting, at this stage

this very nonlinear process was constructed and provisionally, that critical flow was not reached in

solved, with qualitative agreement with several the throat but at the end of the experimental

observations. Computer simulation of the channel. This possibility may lead to a revision

phenomenon was begun, with an- eye to the of our views on choking in two-phase flow.

study of laser-induced shock waves and to

sorting out the "energy bookkeeping" -the The second task seeks to apply the methods of

ultimate destinations of the laser energy. classical ("conservative") thermodynamics to

self-consistent formulations of constitutive laws

descriptive of inelastic deformations,.damage and

Brown University fracture, with special emphasis on plastic

Division of Engineering $117,000 deformation. The identification of the internal

Providence, RI 02912 06-C variables and their associated intensive affinities

90-1 is essential for the calculation of entropy and for

Two Studies of Nonlinear Processes in the derivation of explicit formulae which are

Irreversible Thermodynamics -- descriptive of the local rate of entropy production

J. Kestin in each system.

The project studies two potentially productive Good success has been achieved with the

lines of-research into two well-defined problems, formulation of an elementary theory of fracture in

both linked in that they fall into the broad field of cooperation with Professor G. Herrmann of

irreversible thermodynamics. Stanford University which resulted in two joint

papers.

The first task studies a mathematical formalism

for the qualitative analysis of the

geometric-topological structure of all trajectories University of California,

(solutions) of a mathematical model of Berkeley

two-phase flow conducted in a phase space Dept. of Electrical Engineering $89,775

formed with the thermodynamic state variables, and Computer Sciences 06-C

the velocities of the two-fluid phases and the Berkeley, CA 94720 90-3

space variable.

Self-Generated Stochastic Heating in an RF

The most important result of the analysis is a Discharge

complete resolution of the problem of choking AJ. Lichtenberg, M.A. Lieberman

The theory leads to a classification of points in

phase space into: (a) regular points; (b) turning The purpose of this project is to study electron

points; and (c) singular points. Points (a) are not heating mechanisms in radio frequency (r.f.)

descriptive of choking, and through them there discharges. These discharges are used

passes one and the only one trajectory. Points extensively by industry for surface modification of

(b) describe choking at the end of the channel, electronic and mechanical materials. In addition

and points (c) describe choking inside the to the usual r.f. ohmic heating in the plasma

channel. The analysis is applicable to a wide interior, it has been found theoretically that

class of mathematical models of two-phase flow stochastic heating at the plasma surface plays a

now employed in industry and makes use of the major role. The stochastic electron heating

powerful tools of the mathematical discipline of arises from successive decorrelated reflections of

dynamical systems.

Engineering Research 4 1990
electrons with the oscillating sheath near the The effective thermal conductivity of single and

surface of the discharge. Power is also binary particle size packed beds saturated with

transferred directly to the ions by acceleration in stagnant gas was determined numerically.

the sheaths. The efficiency of stochastic heating Engineering correlations were developed for

depends on the detailed sheath dynamics. For binary mixtures with various particle sizes,

a low pressure discharge at a pressure of 3 solid/gas conductivity ratios and gas pressures.

mTorr, power of 100 watts, and frequency of 13 Forced convection in a packed tube with axial

MHz, 95% of the electron heating is predicted to dispersion is being modeled to further test our

occur stochastically. hydrodynamic dispersion model. The effect of

dispersion on the onset of natural convection in

The sheath dynamics are being measured and a porous layer with volumetric heating is

related to the predicted stochastic heating for a presently under investigation. The effects of the

plane parallel argon discharge. Depending on dispersion on finite amplitude behavior including

the details of the sheath motion, the bifurcation of the initial flow will be studied.

enhancement factor of the stochastic heating can

change, and consequently so can the ratio of Steam injection into a uniform downward water

electron to ion power at a given overall power flow in a porous channel has been studied both

level. The measured results, together with experimentally and theoretically. Conditions for

measurements of other plasma parameters, will oscillation of the resulting steam-water interface

be used to construct better predictive models of have been delineated and its effect on heat and

discharge behavior and parameter scaling. mass transfer augmentation has been measured.

Steam bubble size and shape, surrounding water

Stochastic heating can be enhanced with a temperature field, and pressure drop at the

resonant helical discharge structure. This injector have been measured. A more extensive

geometry is of importance for materials study of the oscillatory behavior of the bubble will

processing applications and is under follow. In the theoretical studies, steam zone

investigation as part of the overall program to shape, steam and water flow and temperature

understand plasma heating and develop models fields, local condensation rate, and average

of r.f. processing discharges. Nusselt number have been found by solving the

continuity, momentum, and energy equations for

both water and steam using a hodograph

University of California, transform and an integral method for Darcy flow.

Los Angeles Numerical modeling of the onset of bubble

~L~~~os AMngeles ~oscillation will be investigated for non-Darcy Mechanical, Aerospace, & Nuclear $75,760 flows

Engineering Department 01-C

School of Engineering and 89-3

Applied Science

Los Angeles, CA 90024-1597

Basic Studies of Transport Processes in

Porous Media

I. Catton

This project is an ongoing study of single- and

two-phase convective processes in porous

media. The objective of this work is to develop

physical understanding of the governing

phenomena and models of the transport

processes by theoretical and experimental

means.

Engineering Research 5 1990
University Of California, Correspondence of these predictions with Los Angeles experimental results is quite favorable, especially L~OS~ An~gel~es~ in that the modeling contains no empirical Mechanical, Aerospace, & Nuclear $27485 correlations or adjustable parameters.. Current

Engineering Department 06-B efforts are focused on the representation of

School of Engineering & 90-1 ignition in the liquid jet by accounting for finite

Applied Sciences rate chemistry.

Los Angeles, CA 90024-1597

Modeling of the processes of evaporation and

Studies in the Combustion and.Breakup of combustion for a single, axisymmetric fuel droplet

Transverse Uquid Jets and Fuel Droplets in a convective environment is also undertaken

AR. Karagozlan here. The influence of the internal flowfield on

various flame characteristics is computed, and

The present studies are concerned with the predicted variation of droplet size in time is

analytical modeling of the processes of mass compared with experimental measurements. At

loss, breakup, and burning in liquid fuel jet present fast chemistry is assumed but future

streams injected transversely into a crossflow of studies will include the incorporation of finite rate

air and in single liquid fuel droplets present in a chemistry in order that ignition and other flame

convective environment. This multiphase flow stabilization characteristics may be studied.

study emphasizes the effect of the internal

vortical structure of the liquid on important

physical features of these reacting flowfields, i.e., University Of California,

1) the incompressible vortex pair flowfield within

the cross-section of the liquid transverse jet, and Los Angeles

2) the Hill's spherical vortex within the Mechanical, Aerospace, & Nuclear $84,283

axisymmetric liquid droplet. Engineering Department 06-C

School of Engineering & 89-3

Since the inception of this grant, our efforts have Applied Sciences

focused on modeling of the deflection, mass loss, Los Angeles, CA 90024-1597

breakup, and burning of the liquid transverse jet

in compressible crossflow, for a chemical Modeling of Energy and Particle Transport

reaction with fast kinetics. Inviscid, compressible G.C. Pomraning

flow about the elliptical cross-section of the jet is

solved analytically in the low subsonic regime The goal in this research is to develop a

and numerically for upstream Mach numbers comprehensive theory of linear transport/kinetic

above 0.3. External boundary layer analysis theory in a stochastic mixture of solids and

along the surface of the cross-section allows immiscible fluids. Such a theory should predict

determination of an effective drag associated the ensemble average and higher moments,

with the jet, which balances centripetal forces such as the variance, of the particle or energy

resulting from jet deflection. The presence of a density described - by the underlying

diffusion flame in the boundary layer for transport/kinetic equation. The statistics to be

upstream Mach numbers less than 0.3 is studied correspond to N-state discrete random

represented, and fuel mass loss due to variables for the interaction coefficients and

evaporation as well as combustion is computed. sources, with N denoting the number of

Mass and momentum balances are then components in the mixture. The mixing statistics

performed along the jet, so that fuel jet and to be considered are. Markovian as well as more

flame trajectories, bow shock penetration (if '.general statistics.

present), and effective flame length may be * ,

determined. An approximate technique for In the absence of time dependence and

predicting jet breakup location is also developed, scattering, the theory is well developed and

based on a balance of stresses and a local sonic described by the master (Liouville) equation for

point (if present) adjacent to the deflected jet. Markovian mixing, and by renewal equations for

Engineering Research 6 1990
non-Markovian mixing. The Intent of further simulation. A long term goal of this aspect of the

work is to generalize these treatments to Include research includes the attempt to discover higher

both time dependence and scattering. A further dimensional solitons.

goal of this research is to develop approximate,

but simpler, models from the comprehensive The key concept of adiabatic invariance underlies

theory. In particular, a specific goal is to the Issue of integrability and stochasticity in

formulate a renormalized transport/kinetic theory dynamical systems. The extent to which the

of the usual nonstochastic form, but with effective action variable is conserved is being calculated

interaction coefficients and sources to account with the goal of predicting experimental

for the stochastic nature of the problem. arrangements in which the exponentially

Numerical comparisons of all models will be suppressed deviations from adiabaticity can be

made against Monte Carlo simulations which probed and compared to theory.

involve a straightforward average of solutions for

a large number of physical realizations of the

statistical mixing. Extensions to nonlinear kinetic University of California,

equations will also be investigated. San Diego

Scripps Inst. of Oceanography $156,000

La Jolla, CA 92093-0402 06-C University Of California, a Jolla, CA 9209-0402 90-

Los Angeles Signal Processing in Chaos

Department of Physics $73,000 H.D.I. Abarbanel

Los Angeles, CA 90024 06-C

90-3 We are investigating methods for modeling fluid

Wave Turbulence and Self-Localization In flows and plasma dynamics of relevance to

Continuous Media energy problems when these physical

S. Putterman phenomena exhibit motion on fractal objects

called strange attractors. In these cases, which

Nonlinear wave interactions in far off equilibrium are quite common both in the settings indicated,

systems are being studied with the goal of and in electrical circuits and condensed matter

understanding the development of stochasticity systems, the time series have continuous

and the formation of localized coherent broadband power spectra and quite irregular

structures. From the general theoretical point of behavior. We are engaged in methods for

view one long term goal is the determination of identifying the space in which to work for these

the probability distribution for a sea of nonlinear systems (phase space reconstruction), methods

interacting waves. This problem is being for computing the invariants of the motions, and

approached via the extension of the Fokker- methods for making physical models for

Planck formalism to include ultra long time scales prediction in these irregular systems. These

and higher order correlations. From the practical systems are inherently less predictable than

point of view these ideas are being applied to the familiar linear systems, but their predictability is

propagation and interaction of waves on the nonzero and may be extracted in a systematic

surface of a fluid that is strongly driven. fashion from the time traces themselves.

At high amplitudes, propagating waves can also The work in FY90 has concentrated on methods

form localized structures such as kink, breather to extract chaotic, deterministic signals from

and envelope solitons. These structures as well noisy measurements. The noise may be due to

as recently discovered nonlinear domain walls environmental conditions or measurement errors

are being studied from the theoretical as well as or may have been imposed on purpose to mask

experimental perspective. The experiments are the signal. With these 'cleanings tools, we will

being carried out on fluids and nonlinear lattices clean up laboratory and field data for use in the

and are subject to analysis by computer other parts of the signal processing effort.

Engineering Research 7 1990
University Of California, for solving partial differential equations appear

San Diego useful and promising. Expectations of their S9o~~an DU~iego ,capabilities on future machines are now being Institute for Nonlinear Science $20,000 estimated.

La Jolla, CA 87545 06-C

90-1

Lattice Gas Simulation of Fluid Flows Uiv iy of C i i,

B. Hasslacher8. Ha~ssl~ach~erUniversity of California,

San Diego

Lattice gases, operating as cellular automata and Department of Applied Mechanics $117,000

amendable to massive parallelism, which and Engineering Sciences 06-B

simulate the Navier-Stokes equation in two and La Jolla, CA 92093 90-3

three dimensions, were introduced in 1985 by

the principal investigators (Phys. Rev. Lett.). Fuel Droplets Subject to Straining Flow

Such lattice gases are formed of 'Boolean PA Ubby, i F.A. Williams

molecules" with discrete time, space, and

velocity. Their collision laws are designed to This research involves a combined experimental

conserve particle number and momentum. and theoretical effort related to the behavior of

Macroscopic momentum averages satisfy the fuel droplets. The experiments concern the

incompressible Navier-Stokes equation, in a determination by photographic means of the

suitable physical limit. Groups in the United trajectories and under the circumstances

States and in France are already engaged in involving mass loss, of the radius histories of

theory, simulations, and hardware projects for individual droplets in well defined, nonuniform

lattice gas hydrodynamics. Preliminary results laminar streams. Initial research involved three

indicate that the method is easy to implement such flows of increasing 'simplicity: a

(with or without boundaries), robust, and nonpremixed laminar flame in a counterflow

reproduces known hydrodynamic phenomena. It configuration, isothermal counterflowing nitrogen

may eventually yield a new simulation strategy streams, and a vertical Poiseuille flow. In the

for complex turbulent flows, with many practical first two flows unexpectedly large lift forces are

applications. found to act on the droplets. The magnitude of

the lift suggests that its cause is a rapid change

It was proposed that the lattice gas method be in the direction of the. relative velocity vector

evaluated, and that modified models with higher resulting in an unsteady normal force identified

Reynolds numbers be studied. Two-dimensional with lift. This conjecture is presently under

computer models were created to run on the experimental investigation in a fourth flow;

CRAY-XMP, the CRAY II, and on the involved is a horizontal laminar jet with a well

Connection Machine II (a computer with 65,000 defined, top hot velocity profile into which

central processors). These models ran at the rate vertically dropping droplets are injected. Thus

of 80,000,000, 10,000,000, and 2,000,000,000 the droplets experience a sudden and well

cell updates per second, respectively. defined change in relative velocity. The data for

Comparisons with other calculational methods various droplet sizes and jet velocities are

have been done. A three-dimensional program presently being reduced. The general conclusion

has been developed which produced the highest reached from these studies to date is that the

Reynolds numbers attainable with 24 bits usual engineering formulas for the forces on, and

required per cell. Flow past a square plate has heat and mass transfer to, droplets lead to

been successfully modeled by this code. considerable errors under the severe conditions

Summaries of this and other recent work has existing in these flows. The results for Poiseuille

been published in several articles in the August flow show that droplets injected downward offissue of Complex Systems. Lattice gas methods axis experience small amounts of lift causing

them to migrate toward the axis in qualitative

Engineering Research 8 1990
accord with low Reynolds number theory of trajectories (STAT). This method has now been

spheres in pure shear flows. Surprisingly large extended to some nonlinear systems and to

increments in.drag over that for uniform flow at smooth fluctuation processes with superimposed

the same Reynolds number are found. The shot noise. Different methods have been applied

Reynolds number range of our data is from 0.7 to 'systems driven by correlated Gaussian

to 10. Further experimental studies along these fluctuations in the limits of short and long

lines are planned including flows involving correlation times. The unification of existing

significant chemical kinetic effects. In our theories for short correlation times has shown

theoretical work the new model we developed for them to give equivalent results. Numerical

the 'combustion of droplets in a quiescent simulations confirm that these results are useful

ambient involving water gas shift equilibrium at over practical ranges of parameter values. At

the-flame has been combined with a detailed the other end of the spectrum, we have

multicomponent description of diffusion. It is produced a theory valid at long correlation times.

found that- the predicted mass loss is little

affected by either the chemistry or transport We have begun to address the problemi,' of

model but the position of the flame sheet and chemically reacting systems in which spatial

thus the detailed distributions' of species are diffusion plays a role.' Of particular interest have

greatly 'influenced. 'Finally, our work on been open systems of A and B molecules that

applications of the spray equation to a laminar annihilate one another upon (suitably defined)

flame propagating in a cloud of fuel droplets with contact. '-The molecules are replenished by

a distribution of droplet sizes is continuing. external sources that are spatially and temporally

* ..... random. There are numerous applications for

such processes ranging from chemical reactions

University Of California, to electron-hole combination processes. In finite

Uan Divierst y^ systems of dimension 2 or less there is San Diego spontaneous segregation of chemical species Inst for Nonlinear Science, R-002 $171,916 over macroscopic length scales; in infinite

La Jolla, CA La 92093 Jolla, CA .. 06-C 06-C systems segregation is observed if the dimension

*heSto , sic ,89-3 

S is 3 or smaller. These are interesting examples The Stochastic Trajectory Analysis of spontaneous pattern formation.

Technique (STAT) Applied to Chemical,

,Mechanical and Quantum Systems.

'K.Ulndenjberg -.-. : : University Of California,

A number of important physical problems are San Diego

described.. by dynamical equations containing - Department of Physics $ 99,806

fluctuating, parameters; Most theories have until La-Jolla, CA 92093 01-B

.recently assumed the. fluctuations to' be ' 90-3

delta-correlated, thus restricting the scales of the Traveling-Wave' Convection in Fluid

spatial and/or temporal :inhomogeneities to be Mixtures

much shorter than the response scales of the C.M. Surko

system. This assumption is:often. known to be

quite unphysical, especially in nonlinear systems While some progress has been achieved recently

in which .all scales ;are present. Of particular in the-understanding of the dynamics of free

interest in this;program are chemical reactions in convection occurring in single component fluids,

dense media with fluctuations arising from spatial much less is known about the phenomenology of

inhomogeneities. and thermal effects. . convection in fluid mixtures. Yet in realistic

... : . ~. .... . .situations .,. ~. it is the latter that play the important

A ,number: of methods: to deal with 'correlated role. - Examples of interest to engineering include

fluctuations. have been developed under this stability of double-diffusive systems, e.g. solar

program. One involves an explicit construction of ponds, solidification of metal alloy casts,

convection in fuel droplets, and so on.

Engineering Research 9 1990
The proposed research addresses the interaction The work utilizes computer-enhanced

of traveling waves with convective motion in a shadowgraph imaging to visualize the convective

binary fluid mixture. Preliminary results show: flow patterns. The technique can detect the flow

that in a relatively simple experiment .the field even when the convection threshold. is

behavior of the system is such that on varying exceeded by only 0.1%. In .parallel,

one or two control parameters the whole gamut high-resolution heat-flux .measurements are

of states ranging from a laminar traveling-wave made with a resolution -of 0.05%. Thus, the

state to well developed turbulence can be relationship between the pattern and the heat

traversed. Specifically the experimental setup transport can be studied in great detail.

consists of an annular channel with a large

radius. In it a water-ethanol mixture is heated In pure fluids, we are investigating the

from below giving rise to free convection. mechanisms for the convective onset. In most

However, under certain conditions, in addition to physical systems the flow is initiated by

this expected phenomenon, there occur properties of the experimental cell which lead.to

traveling-waves irteracting in complicated ways an imperfect bifurcation. Recently it has been

with the patterns driven by natural convection. possible, however, to perfect the apparatus to a

The resulting oscillatory convection seems to be point where stochastic effects control the

prototypical of similar phenomena arising in' evolution of the flow.

many contexts, ranging from oceanic motion to.

instabilities in liquid crystals. Beyond the convective threshold we are

interested in the evolution and stability of various

The proposed research will address three related convective patterns in containers with simple

topics: 1) weakly nonlinear traveling waves in sidewall geometries. We expect that our results

one dimension; 2) nonlinear pulses in an will help in the development of theoretical models

annulus; and 3) measurement of concentration for pattern stability.

field.

A particularly interesting pattern-stability problem

occurs in binary-mixture convection. For certain

University Of California, Santa values of the parameters of this system, there

Barbara exist spatially localized patches of travelling waves of convective rolls. The existence of.

Department of Physics $121,000 these states cannot be explained by the usual

Santa Barbara, CA 93106 06-C models with relaxational Cdynamics, but rather

90-3 seem to require non-potential theories. We are Bifurcations and Patterns in Nonlinear studying quantitatively the wavenumber,

Systems frequency, amplitude, and spatial extent of these

G. Ahlers, D.S. Cannell localized states. This information will permit a

distinction between several competing theoretical This project consists of experimental models

investigations of non-linear non-equilibrium

fluid-mechanical systems, with an emphasis on

heat transport, pattern formation, and bifurcation

phenomena. These issues are being studied in

Rayleigh-Benard convection, using both pure

and multi-component fluids. They play an

important role in such energy-related issues as

crystal growth from a melt with and without

impurities, the catastrophic inversion of salt lakes

such as the Dead Sea, energy production. in

solar ponds, and various oceanographic

phenomena.

Engineering Research 10 1990
University of California, Santa method to provide quantities which are difficult to

obtain by flow visualization and single-point Barbara velocity measurements. The numerical

Department of Chemical and $92,806 computations were shown to capture the basic

Nuclear Engineering 01-C physics which is associated with the turbulence

Santa Barbara, CA 93106 88-3 generation due to shear.

Turbulent Structure in Uquid Streams The three-dimensional Laser-Doppler

Bounded by a Free Surface and a Solid Wall velocimeter was assembled, and the hardware

S. BanerJee, G. Hetsroni and software were readied for the

measurements. The measurements with the

This project is aimed at studying basic turbulence LDV will be complemented by visualization by

structure in a liquid which flows in a horizontal means of the oxygen bubbles and high speed

flume. The experimental techniques used in this video.

study include a three-dimensional Laser-Doppler

velocimeter, with a 50m measuring volume; and

an oxygen bubble tracing technique with high Ca Mellon nivers

speed videos and flash photography. arnegie eon niversity Chemical Engineering Department $146,786

The oxygen bubble technique resulted in & Graduate School of Industrial

capturing of the detailed turbulence production at Administration 03-A

the solid wall and at the liquid-air interface. The Pittsburgh, PA 15213 89-4

details of the high speed-low speed velocity

streaks at the wall, the coherent structures near Integration of Redesign Methodologies for

the wall, and the turbulent bursts were visualized Chemical Processes

and measured. It was found that the turbulent LT. Begler, I.E Grossmann, G.L

coherent structures reach the interface and are Thompson, AW. Westerberg

visualized there as patches. These patches then

have a profound effect on the heat and mass Process redesign, commonly known as retrofit, is

transfer at the interface. a major task in the chemical industries. However,

most systematic design strategies have been

High speed and low speed velocity streaks were developed for new processes and often do not

also observed at the liquid-gas interface, when apply. This project addresses the development

shear was applied on the liquid by the gas of systematic design methodologies for the

flowing cocurrent or countercurrent to the liquid, redesign of chemical processes. This integrated

The coherent structures from the interface were approach deals with a broad range of problems

then observed to be ejected downwards. in process redesign. Here we discuss progress in

the following areas:

Waves, which were generated by a wave

generating machine, were observed to have a 1) Development of Efficient Optimization

profound effect on the frequency of ejections of Algorithms for Discrete and Continuous

the,coherent structures at the wall. The effects Vaables. Efficient decomposition strategies for

of the wave amplitude and wave length on the nonlinear programming have been developed for

frequency and strength of the turbulent bursts large-scale process optimization. These are

are now being analyzed. . currently being tailored to various problem types.

G. Thompson has also been working on the

These experiments were complemented by solution of several large scale combinatorial

numerical computations. The full Navier-Stokes optimization problems that frequently occur in

equations were solved by a pseudospectral chemical engineering applications, namely,

travelling salesman, and set covering (and

partitioning) problems. He has been

Engineering Research 11 1990
implementing previously devised algorithms on of these theories on experimental hardware. A

various sequential and parallel computers such modular manipulator system consists of a set of

as the CRAY YMP and the Butterfly. link and joint modules of various sizes which may

be assembled together in a desired kinematic

2) Redesign of Multicomponent Separation configuration to achieve a specific task. The

Sequences. Short-cut analysis methods have RMMS design emphasizes modular manipulator

been developed for complex columns components having consistent mechanical and

configurations. For redesign, a two step electrical interfaces. The uniform interfaces will

approach first assesses the capability of existing allow either semi-skilled field personnel or

equipment to accomplish all or part of the another manipulator to rapidly configure a RMMS

alternative separation tasks. Second a manipulator to meet specific task requirements.

superstructure embedding these alternatives This basic research effort will address the

within existing and new equipment is created problem of mapping tasks into a manipulator

which allows for traditional, parallel and serial configuration, formulation of control algorithms for

sequences to be discovered which will minimize the mapped configuration, and experimental

annualized cost. These strategies are being verification of the developed ideas. Though it is

tackled with a scenario approach as well as with not the primary objective, we believe that building

mixed-integer nonlinear programming (MINLP). prototype experimental modules for

demonstrating our ideas will also contribute to.

3) Redesign of Energy Management Ssystems. the technology of modular manipulators.

New mixed-integer nonlinear programming

(MINLP) models have been developed for both For configuring a manipulator from task

the grassroots and the redesign problems. The requirements, we will develop methodologies that

unique feature of these models is the fact that map the task requirements into a specific

the level of energy recovery and selection of manipulator. The kinematic task requirements

matches is optimized simultaneously without will be used to determine the link lengths and the

fixing temperature approaches. In addition the orientation of the modules. And the dynamic

case of multistream exchangers has been task requirements will be translated to obtain the

considered. sizes and ratings of the actuators or joints. The

use of both rule-based expert systems and

4) Redesign for Flexibility. Controllability and optimization techniques will be investigated in

Reliability. New measures are being developed obtaining a solution to this problem. For

that can integrate these different operability effectively controlling modular manipulators

characteristics. A stochastic framework is-being (RMMS), a methodology for automatically

used to integrate flexibility and reliability. In configuring a controller will be developed using

addition,we - are also focussing on the model-based and/or adaptive control techniques

development of optimization-based control

methods for constrained, nonlinear processes. :

University Of Chicago

Department of Chemistry $156,707 Carnegie Mellon University Chicago, IL 60637 06-C

Department of Electrical and $94,814 89-3

Computer Engineering 03-C Topics In Finite-Time Thermodynamics

Pittsburgh, PA 15213 89-3 R.S. Berry

Research on a Reconfigurable Modular The objective of this research is the analysis in

Manipulator System thermodynamic terms of the performance of

P.K. Khosla, T. Kanade systems and processes subject to time or rate

constraints. Part of the research deals with

The goal of our research is to address the basic developing methods for conducting analyses,

theories of reconfigurable modular manipulator such' as emerged from the introduction of a

systems that will culminate in the demonstration suitable metric in the space of thermodynamic

Engineering Research 12 1990
variables and the evaluation of path lengths caustic on the absorber. This principle proved

with that metric. The lengths so obtained have sufficiently elastic to accommodate most

been shown to be directly related to the boundary conditions in two dimensions (i.e.,

dissipation associated with the path. Another linear geometry). Ideal solutions in three

piece of recent work at this basic level just dimensions have also been formulated. Our work

completed under this project is an attempt to on vector flux has led to a reexamination of the

introduce a variational formulation of foundations of radiometry with emphasis on

irreversible heat transfer and diffusion, which is observable effects. Our theoretical work on

intended to apply in nonlinear as well as linear nonimaging designs has led to demonstration of

situations. ultra-high flux from sunlight which exceeds

previous results by substantial factors.

The other aspect of this research is the

application of the general methods to the

analysis of specific systems of current interest. Clarkson University

During the initial period of the project, the Dept of Chemical Engineering $56,816

stopping of a beam of atoms by absorption and Potsdam, NY 13676 01-C

remission of laser light was analyzed and the 88-3

entropy changes in the process were Droplet Motion in Numerically Simulated

evaluated. The reduction in entropy of the Turbulence

atomic beam due to cooling and stopping is J.. McLaughlin

compensated a thousandfold over by the

increases in the entropy of the light due to The primary goal of the research is to obtain

randomization of the phase, the polarization information about the dispersion of aerosol size

and especially the propagation direction. droplets and particles in a turbulent channel flow.

It is assumed that the flow is vertical so that

aerosols do not sediment onto the channel walls.

University Of Chicago The behavior of aerosols in the viscous wall

The Enrico Fermi Institute $141,750 region is of particular interest since it has been

Chicago, IL 60637 06-C suggested that shear induced lift forces may be

90-3 very significant in this region. The approach -

Fundamentals and Techniques of involves numerical integration of the aerosol

Nonimaging Optics for Solar Energy particle equation of motion to obtain the

Concentration trajectories of the droplets or particles. In order

R. Winston to perform such calculations, the undisturbed (by

the particles) velocity field of the fluid is needed

Nonimaging optics departs from the methods of and this is supplied by a direct numerical solution

traditional optical design to develop instead of the Navier-Stokes equation using

techniques for maximizing the collecting power of pseudospectral methods. The fluid velocity is

concentrating elements and systems. Designs used to evaluate the Stokes drag force and the

which exceed the concentration attainable with Saffman lift force in the aerosol particle equation

focusing techniques by factors of four or more of motion. By comparing runs in which the lift

and approach the theoretical limit are possible. force is dropped with runs in which it is retained,

This is accomplished by applying the concepts of one can obtain information about the importance

Hamiltonian optics, phase space conservation, of shear-induced lift on aerosol motion.

thermodynamic arguments, and radiative transfer

methods. In the early nonimaging designs the

might edifice of aberration theory was dismantled

and replaced by a single key idea. According to

this, maximum concentration is achieved by

ensuring that rays collected at the extreme angle

for which the concentrator is designed are

redirected, after at most one reflection, to form a

Engineering Research 13 1990
University Of Connecticut This work is being done with the cooperation of

Dept of Mechanical Engineering " $47,804 Engineering Science Software, Inc. working

Storrs, CT 06268 01-A under a related contract. Single crystal

88_3 specimens have been provided by Pratt and

Micromechanical Viscoplastic Stress-Strain Whitney, Inc.

Model with Grain Boundary Sliding

E.H. Jordan Cornell University

The goal of this research is the development and Sibley School of Mechanical and $97,952

verification of a model of the time and history Aerospace Engineering 01-C

dependent viscoplastic deformation behavior of Ithaca, NY 14853 88-3

polycrystalline metals. Single grain behavior has

been derived by summing postulated slip Experiments in Turbulent Mixing

behavior on crystallographic slip systems.. Multi Z Warhaft

grain behavior will be obtained by summing

deformation occurring in different grains while This project is concerned with experimental

accounting for grain interaction through a self studies of scalar mixing in fully developed

consistent micromechanics approach. The turbulent flows, a subject relevant to our

model will also represent grain boundary sliding understanding of chemical reactions, combustion

through the use of a solution recently published and environmental pollution. Mixing in both

by T. Mura. e ' homogeneous and inhomogeneous turbulence,

--v- ,with and without the effects of buoyancy is being

High temperature experiments on Hastelloy-X examined.

will be used to verify the model. Single crystal

properties used for input to the model are The first experiment concerns scalar dispersion

currently being determined. -Using these and mixing in a shearless "second order" mixing

properties the behavior of polycrystal layer. Here various turbulence generating grids

Hastelloy-X will be predicted and then compared are designed so that large turbulent eddies on

with polycrystalline experiments recently one side of the flow mix and diffuse with smaller

completed. Prediction of these tests constitute a eddies on the other side of the flow. The

critical test for:the theory. . porosity of the grid is such that the mean flow

remains constant across the grid and hence

The model will not only predict the viscoplastic there is no mean velocity shear or turbulence

response of polycrystals but also will allow production. Thus, the spreading rate in the

metallurgical findings usually stated' in mixing region is determined solely by

crystallographic. terms to;.be more directly turbulence-turbulence interactions. This flow,

incorporated into the model. The explicit although in some respects more fundamental

calculation of grain boundary sliding will help than the turbulence mixing layer with shear, is

illuminate the role played by grain boundary poorly understood. The flow is unusual in that it

sliding in the overall deformation during complex is homogeneous in the mean but has large scale

load histories. Grain boundary : sliding intermittence and the turbulence is

deformation plays an important role in material inhomogeneous. Scalar dispersion from the thin

damage and the model should be useful in life thermal line source placed in the center of the

prediction under complex variable temperature flow is also being studied.

conditions.

The second main experiment is concerned with

At present, the single crystal model is available scalarmixing in stably stratified decaying grid

and the self consistent model without grain generated turbulence. A temperature (density)

boundary sliding has'been derived and is being gradient is formed at the entrance to the plenum

programmed. ' chamber of the wind tunnel and then the flow is

passed through a turbulence generating grid.

Engineering Research 14 1990
The negative buoyancy causes the heat flux to The exertia and added-mass coefficients have

decay (and in some cases reverse sign) and been computed for various geometrical

there is a complex interaction between the arrangements of spheres, both in an infinite array

various components of turbulent kinetic energy and in tubes. Comparable measurements were

and the potential energy. Single and multiple made by measuring the natural frequency of

line source dispersion experiments on mixing oscillation of such arrays in water. Future

across sharp temperature steps, with and without experiments are planned in which more

buoyancy, are being attempted. properties, such as pressure fluctuations, are

measured.

Dartmouth College Theoretical and experimental efforts are

Thayer School of Engineering $110,461 underway to obtain realistic interphase forces

Hanover, NH 03755 01-C including the effects of viscosity and drag.

88-3 Computations show that the effects of pressure

Two Phase Potential Flow gradient, added mass, phase change and drag

G.B. Wallis do not add linearly except at low Reynolds numbers. This has implications for the transient

The objective is to develop theorems for two- response and stability of fluidized beds.

phase potential flow analogous to those existing

for single phase flow. Duke University

Using one function, the "exertia," which describes Mechanical Engineering and $65,000

the external fluid inertia due to relative motion of Materials Science Department 01-C

suspended particles, it has been possible to Durham, NC 27706 90-3

derive the average stress tensor, kinetic energy,

overall momentum flux tensor and equations of Analytical and Experimental Study of

motion for uniform systems of particles and the Instabilities in Buoyancy-Driven Convection

effective Bernoulli equation for the fluid flowing in Porous Media

through a stationary array of particles. J.G. Georgladis

Recent developments include more general The mission of this research project is the study

descriptions of the mean particle stresses and of thermal instability phenomena associated with

the averaged Bernoulli equation for the fluid natural convection in two classes of fullywhen both phases have a general motion. Unks saturated porous media systems: (i) porous

have also been established between this media saturated with pure fluids, and (ii) porous

approach and Geurst's variational methods media saturated with binary fluids. Our primary

including the derivation of equations of motion for objectives are: (1) the delineation of the various

each phase, it being possible for the dispersed stability domains for the convective flows and an

phase to be compressible. exploration of the convective states after the

onset of secondary instabilities, (2) the

The equations of motion for each phase have development of novel experimental techniques

also been expressed in terms of a mutual for high precision measurements and

"interfacial pressure tensor" that is related to both determining the flow patterns in porous media,

the average stress in the dispersed phase and and (3) the validation of macroscopic governing

the net force on the continuous phase. This equations for natural convection in porous media.

interfacial pressure tensor is also closely coupled

to the Reynolds stresses in the continuous Emphasis is put on the first two objectives. An

phase. experimental investigation of the onset of natural

convection in a porous medium with internal heat

generation is initiated. The potential of Magnetic

Engineering Research 15 1990
Resonance Imaging (MRI) techniques in The FORTRAN software will allow metallurgical

visualizing low-speed flows in porous media is and micromechanical work reported in the

also investigated. We will explore ways of literature to be easily embedded in a constitutive

obtaining quantitative information on interstitial (stress-strain) framework for analyzing the

velocity profiles by using a combination of spin overall deformation response of polycrystalline

tagging and spatial encoding MRI processes. metal aggregates under thermomechanical

Direct numerical simulation and stability analysis loading conditions.

of the pertinent convective states will be

performed in conjunction with the experimental

component of this investigation. University Of Houston

Dept of Mechanical Engineering $122,163

Houston, TX 77204-4792 01-C

Engineering Science Software, 88-3

Inc. Comparative Study of the Vorticity Field in

Smithfield, RI 02917 $46,048 Turbulent Flows: Theory, Experiments,

01-A Computations

A Micromehanical Viscoplastic 88-3 A.K.M. Hussain

Stress-Strain Model with Grain Boundary

Sliding This is a unified research effort involving

KIP. Walker experimental, numerical and theoretical works to

address the basic mechanisms of turbulence

The aim of the project is to develop a phenomena in shear flows via studies of its

viscoplastic constitutive model, with vorticity field. Experiments are being performed

accompanying FORTRAN software, to model the in jets and wakes to educe the coherent

deformation behavior of polycrystalline metals structures on the basis of the instantaneous

comprised of an aggregate of fcc single crystal vorticity maps obtained by one or multiple rakes

grains whose crystallographic axes are oriented of X-wires. Through an eduction algorithm

at random. The single crystal grains are developed by us, vorticity patches are aligned

assumed to be spherical and are modeled with through cross-correlation and ensemble

an anisotropic viscoplastic theory based on averaged: whatever survives the ensemble

crystallographic slip along the octahedral and average is the 'coherent structure' (CS) and the

cube slip directions of the fcc metal. The overall remainder of each realization is 'incoherent

response of the polycrystalline aggregate is turbulence'. Using coherent vorticity, production

assumed to be isotropic and is deduced from the and Reynolds stress we discuss the topology

single crystal response by means of a and dynamics of CS in turbulent flows, in

self-consistent method. The effect of grain particular in elliptic jets and cylinder wakes. The

boundary sliding between the grains is being same algorithm is applied to direct numerical

modeled in the self-consistent formulation to simulations of turbulent flows and using spectral

assess the importance of including this methods and the results are compared with

mechanism in the overall response of the experimental data. The simulation results

polycrystalline material. provide spatial details of helicity, enstrophy and

dissipative fields.

Experimental tests on single crystal specimens of

the superalloy Hastelloy-X are being run at the As an integral part of this project, we are also

University of Connecticut to determine the studying vortex dynamics using experimental,

material constants in the single crystal numerical and theoretical approaches. We have

constitutive model. The overall response of the focussed particularly on vortex reconnection

self-consistent model of the polycrystalline mechanisms. Experimental studies involve flow

aggregate will then be theoretically determined visualization and hot-wire measurements.

and compared with experimental results from Numerical studies of two anti-parallel vortex

isotropic specimens of polycrystalline

Hastelloy-X.

Engineering Research 16 1990
tubes have revealed three distinct stages of seen to be a stronger function of subcooling than

vortex reconnection: core deformation, bridging velocity. - Previous investigators have reported

and threading. Their implications in turbulent 'that the q,,, to q,, ratio for Freon-113 increases

flows are being explored. A second, from 0.083 for pool boiling to 0.303 for 6.8 m/sec

high-resolution simulation has utilized symmetry at low subcooling levels. In Freon-113

to address higher Reynolds number as well as experiments at 57 C subcooling and 3.53 m/sec,

compressible vortex reconnection. A third study the ratio was found to be 0.77.

has considered collision of vortex rings. In these

we have explored the mechanisms of enstrophy Discontinuities in measured wall temperatures

cascade, and helicity and dissipation fields. We were observed when the vapor film collapsed

have also started theoretical studies of how a over certain portions of the heater prior to the

blob of fluid in a rotational flow produces helicity entire heater being enveloped in nucleate boiling.

outside it and how helicity fluctuations at a These discontinuities are caused by film and

turbulent-nonturbulent interface affect nucleate boiling coexisting in near proximity of

entrainment. Another theoretical-numerical the location of thermocouples used to measure

study has been begun on vortex chaos and local heater temperatures.

thermodynamics of vortices.

It was also observed that the bottom of the

Further studies will involve vorticity and helicity heater underwent an unexpected temperature

fields in laboratory flows with a 9-wire probe in - drop during nucleate boiling for high levels of

conjunction with rakes of X-wires, and subcooling. Such temperature drops were very

comparison with direct numerical simulation. We repeatable. They resembled the "temperature

will also continue the studies of vortex overshoot" phenomena that have been observed

reconnection, effects of compressibility on in pool boiling experiments on a variety of

reconnection, and relation of helicity and vortex heating surface and configurations. However, no

dynamics to turbulence. observable significant increase in nucleation that

is generally considered to be responsible for

such behavior was found in our experiments.

University of Houston

Department of Mechanical Engineering $ 0 An analysis of film boiling for constant wall flux

Houston, TX 77204-4792 01-B conditions for the cylindrical heater yielded

90-1 results that are consistent with experimental

High Flux Film and Transition Boiling data. This analysis, based on a mass-energy

LC. Wifte balance, also predicts the point at which collapse

of the vapor film occurs during transition boiling

The potential for altering the boiling curve reasonably well.

through the effects of high subcooling and high

velocity is being investigated. Uquid flowing

upward in crossflow over 0.635-cm electric Idaho National Engineering

heaters is the configuration that is currently being Laboratory

used. As a part of the study, azimuthal Biotechnology and Geosciences $100,087

temperature variations around the heater during Idaho Falls, ID 83415-2210 06-A

nucleate and film boiling have been measured, 89-3

the manner of onset of film boiling and vapor film Three Phase System Modelling

collapse has been observed and photographed, a Andrews

and the effects of subcooling and velocity on qR,

and q, have been determined. Many unit operations in environmental

engineering, including biological wastewater

Experiments have been conducted at subcooling treatment and flotation (used to remove colloids

levels up to 58 C and at velocities up to 381 from wastewater and sulfur from coal), involve

m/sec for Freon-113, and 95 C and 2.98 m/sec bubbles rising through water containing both

for water. With both, the qg, to q, ratio was surface-active materials and suspended

Engineering Research 17 1990
particles. There is no general theory to predict This project is one of six projects comprising a

the hydrodynamics near millimeter-sized bubbles collaborative research program with the

in this situation, which makes it difficult to predict Massachusetts Institute of Technology.

the gas/liquid mass transfer rate (in biological

wastewater treatment) or the number of particles

that strike the bubble (in flotation). This task will Idaho National Engineering

develop a mathematical model of the situation on Laboratory

the upper surface of the bubble where most La ral

mass transfer and particle capture occurs. The Materials Technology Group $385,706

model will be based on integral boundary layer Idaho Falls, ID 83415-2218 01-A

theory for the hydrodynamics and the transport of 90-3

surfactant to and from the interface, and will Elastic-Plastic Fracture Analysis Emphasis

on Surface Flaws include effect th of adsorbed surfactant an on theFlaws

force balance at the bubble interface. W.G. Reuter, W.R.Lloyd, J.S. Epstein

The results will be compared with experiments The objective is to improve design and analytical

designed to measure the particle capture rate as techniques for predicting the integrity of flawed

a function of surfactant concentration (i.e., structural components. The research is primarily

interfacial tension) and particle concentration experimental, with analytical evaluation guiding

Particle capture rate is measured because it is a the direction of experimental testing. Tests are

very sensitive indicator of bubble interface being conducted on a material (a modified ASTM

motion. A-710) exhibiting a range of fracture toughness but essentially constant yield and ultimate tensile

Idaho National Engineering strength. As test temperature increases, the specimen configuration-fracture toughness

Laboratory relationship complies initially with requirements

Applied Optics $182,137 for linear elastic-fracture mechanics and extends

Idaho Falls, ID 83415 06-A beyond the range of a J-controlled field.

90-3 Presently, compact tension and bend specimens

In-Flight Measurement of the Temperature are being used to develop state-of-the-art

of Small, High Velocity Particles fracture mechanics data for comparisons with

J.R. Fincke data developed from, specimens containing

surface cracks.

Knowledge of in-flight particle parameters is

fundamental to understanding particle/plasma These comparisons are presently underway for

interactions in the physical and/or chemical 6.4 and 12.7 mm thick surface- flawed

processing of fine powders. A measurement specimens. Metallographic techniques are being

technique for simultaneously obtaining particle used to measure crack tip opening displacement

size, velocity and temperature has been and remaining ligament configurations for

developed. Particle size and velocity are comparison with analytical models. Other

obtained from a dual color combination laser techniques including microphotography and

Doppler velocimeter (LDV) and laser particle replicating of the crack tip region to complement

sizing system. The LDV system consists of a the above measurements are being used to

crossed beam technique while particle size is identify limits and capabilities of each technique.

determined from the absolute magnitude of Moire interferometry techniques are being used

scattered laser light. The particle temperature is to evaluate and quantify the deformation in the

determined by a two color pyrometer technique. crack region. These data are being used to

The spatial resolution is better than Imm3 and experimentally" measure J and CTOD for

allows the distribution of particle size, velocity standard (CT and SENB) specimens as well as

and temperature to be mapped over laboratory for specimens containing surface cracks. The

scale flow fields. The influence of particle size, above tests have been supplemented by using

injection rate, torch power, etc., are currently specimens fabricated from aluminum (dimple

being examined in typical flow fields. rupture only) and titanium. The titanium

Engineering Research 18 1990
specimens are being used to study the fracture plasma will be represented by a stochastic

behavior and the ability of existing models to particle model similar to that previously used to

predict failure for weldments. Moire model liquid sprays. This model allows for

interferometry techniques are being used to spectra of particle sizes, shapes, temperatures,

study the local constitutive behavior and the etc., thereby capturing the important statistical

fracture process at the crack tip region of the aspects of the problem. It will include

weldment. Automated techniques are being sub-models for the various plasma-particle and

developed to obtain, store and analyze the moire particle-particle interaction processes, including

data. melting, evaporation, condensation, nucleation,

agglomeration, and coalescence.

Idaho National Engineering

Laboratory Laboratory Idaho National Engineering

Energy and Systems Technology Group $0 Laboratory

Idaho Falls, ID 83415 06-A Materials Technology Group $568,805

90-3 Idaho Falls, ID 83415-2210 06-A

Modeling of Thermal Plasma Processes 90-3

J.D. Ramshaw, C.H. Chang Plasma-Particle Interactions

C.B. Shaw, Jr., T.L Eddy, S.C. Snyder, LD.

Optimization of thermal plasma processing Reynolds

techniques requires a better understanding of the

space- and time-resolved flow and temperature Plasma processing of materials saves energy

distributions in the plasma plume and of the and strategic materials, compared to other

interaction between the plasma and a particulate methods. The high temperatures and

phase. This research is directed toward the temperature gradients unique to plasmas make

development of a comprehensive computational possible the synthesis or destruction of

model of thermal plasma processes and compounds not achievable by other means.

plasma-particle interactions capable of providing However, for American industry to put this

such information. The model is embodied in the plasma technology to practical use, and thereby

LAVA computer code for two- or improve its competitive position in world markets,

three-dimensional transient or steady state it is necessary to minimize the expensive trial

thermal plasma simulations. LAVA uses a and error scale-up from laboratory

rectangular mesh with an excluded volume demonstration through pilot plant experimentation

function to represent geometrical obstructions to full production. This goal requires creation of

and volume displaced by particles. Simple highly a rational basis for plasma torch design and

vectorizable numerics are utilized, with rapid operation, namely, a set of computer models

steady state and low-speed flow options. The (being developed at the INEL and at MIT) which

plasma is represented as a multicomponent fluid have been fully validated by comparison of their

governed by the transient compressible predictions with experimental results of

Navier-Stokes equations. Real gas physics is diagnostic measurements. The role of this task

allowed for by temperature-dependent specific is-to develop the necessary diagnostic methods,

heats and transport properties. Multicomponent make the test results available to the modelers,

diffusion is calculated in a self-consistent and jointly determine what further features are

effective binary diffusion approximation, including needed in both the models and the diagnostics.

ambipolar diffusion of charged species. Both

k-epsilon and subgrid-scale turbulence models While a half dozen diagnostic methods have

are included. Dissociation, ionization, and been developed and tested in this task, in FY

plasma chemistry are represented by means of 1990 attention centered on (1) a suite of

general kinetic and equilibrium chemistry emission spectroscopy measurements,

routines. Discrete particles interacting with the interpreted by the generalized multi-temperature

equilibrium model, to determine the significance

Engineering Research 19 1990
of departure of thermal plasmas from the Idaho National Engineering

commonly assumed local thermal equilibrium; Laborator

and (2) high resolution absolute intensity

measurement of Doppler broadened and Doppler Nondestructive Materials Characterization

shifted laser radiation Rayleigh scattered by the Group $177,371

atoms and ions of the plasma. The latter permits Idaho Falls, ID 83415-2209 03-B

simultaneous determination of the true kinetic 90-3

temperature, local mean flow velocity, and NonDestructive Evaluation of

density of the scatterers. Superconductors

K. L. Telschow

Idaho National Engineering The purpose of this task is to perform Idaho Naonal Engineering fundamental research which will lead to the

Laboratory development and application of new

Materials Technology Group $480,000 nondestructive evaluation (NDE) techniques and

Idaho Falls, ID 83415 03-A devices for the characterization of

90-3 high-temperature superconducting materials. In

Intelligent Control of Thermal Processes the near future, application of these new

H.B. Smartt, J.A Johnson superconductors will require NDE methods for

evaluating the properties of wires, tapes and

This project addresses intelligent control of coatings. Microstructural and, particularly,

thermal processes as applied to materials superconducting properties, must be measured

processing. Intelligent control is defined as the noninvasively in a manner capable of providing combined application of process modeling, spatial information so that fabrication processes

sensing, artificial intelligence, and control theory can be optimized. Although the fabrication of

to process control. The intent of intelligent these ceramic materials is being pursued by

control is to produce a good product without many different techniques at present, there is

relying on post-process inspection and statistical enough similarity in the different superconducting

quality control procedures. The gas metal arc materials and the , fabricated forms to begin

welding process is used as a model system; research into NDE measurement techniques. In

considerable fundamental information on the FY89 this project began identifying techniques

process has been developed at INEL and MIT that can determine critical superconducting

during the past six years. Research is being properties on a local scale. This has resulted in

conducted on an extension of the fundamental the use of AC induced currents in conjunction

process physics, application of neural network- with DC transport currents to determine critical

like dynamic controllers and signal/image currents and dissipation locally. The analysis of

processors, and development of noncontact these measurements is being carried out with the

sensing techniques. Tasks include physics of aid of the London and "Critical State" models for

nonlinear aspects of molten metal droplet supercurrent flow in these materials. These

formation, transfer, and substrate thermal results are being correlated with material

interaction; understanding the relationship of microstructure information and other

neural network structure and associated learning measurement techniques.

algorithm to model development and learning

dynamics in neural networks with the objective of

obtaining a fundamental understanding of

network transfer functions; and advanced

sensing, including the propagation and

interaction of ultrasound in metallic solid and

liquid media.

This project is part of a collaborative research

program with the Massachusetts Institute of

Technology.

Engineering Research - 20 1990 f-~.
University Of Illinois vertical annular flows, and (3) to develop models

Coordinated Science Laboratory $117,612 for the dispersion and deposition of drops and

Urbana, IL 61801 03-A particles in a turbulent flow. Vertical flow

88-3 experiments are conducted in pipelines with

Model Building and Control of Large Scale diameters of 3/4 in., 1 1/2 in., and 2 1/4 in. The

Systems horizontal flow facility has 1,2,3,4 in. pipelines

T. Basar, P. Kokotovic mounted on a specifically designed platform

whose angle can be controlled to within 0.01

This research program aims at a comprehensive degree. Droplet motion in turbulent fows is

study of'some fundamental issues that arise in studied in a vertical 2 in. pipeline and in a

the modeling, control and coordination of supercomputer simulation for turbulent flow in a

deterministic and stochastic large scale systems. channel. A specifically designed facility that

The research plan during the first phase has creates stationary slugs in a pipeline is also

been to extend the relevant existing theories and available.

methodologies in novel directions, covering areas

such as (i) model simplification through Considerable progress has been made in

decomposition and aggregation, (ii) temporal and developing a new mathematical framework for

spatial hierarchies, (iii) goal-orientedhierarchies describing particle motion in horizontal turbulent

and multiple decision layers, and (iv) control and fields, where gravitational settling can be

coordination of large scale systems based on important. This is being applied to understand

(probabilistic) multimodeling. droplet distribution in gas-liquid annular flows

and sediment transport. A Lagrangian

Some of the specific mathematical models that framework is used. The central problem, then

are being used in this context are Markov chains, becomes the description of the behavior of drops

stochastic teams, and. deterministic and or particles originating from a source on the wall.

stochastic teams, and dynamic games, each one To aid in modelling gas-liquid annular flows,

under a number of different information patterns. optical techniques are being used to study

Following this first phase, research is being droplet configurations and drop size.

directed towards developing a new framework, to

allow for distributed and interactive model A central problem in understanding the behavior

building and control, where both structural and of particles in a turbulent fluid is the prediction of

decision making hierarchies evolve over time. A the effect of flow inhomogeneities. This is being

unique characteristic of this approach is that the studied both in computer and laboratory

two independent tasks - modeling and control - experiments. Of particular interest are the

treated heretofore independently, will now be discovery of a mechanism by which particles are

designed to evolve in parallel and trapped at the wall and of a relation of particle

complementarily to each other. impaction on a wall to eddy structure.

In previous work necessary conditions for the

Uni-versity Of Illinois existence of slugs were developed that viewed

DUniversity ptOff ChemIcallEnginering the front of a slug as a hydraulic jump and the

Dept of Chemical Engineering $104,170 tail as a Benjamin bubble. These are now being

I 6 0- tested in special experiments which create

9 -d Fw stationary slugs in a downward inclined pipeline. Gas-Liquid Flow in Pipelines

T.J. Hanratty A comprehensive study of droplet distributions for

gas-liquid annular flow in a 4 inch pipeline was Research is being conducted to obtain a better completed. These gave the unanticipated result

understanding of gas-liquid flow in horizontal that a secondary flow can be initiated in the gas

and vertical pipelines. The goals are (1) to fo because of the presence of drops.

model slug flow and to predict when slugging will

exist in horizontal gas-liquid flows, (2) to obtain

improved predictive methods for horizontal and

Engineering Research 21 1990
University Of Illinois At viscous fluids, although the measured friction

Chicago factor is in good agreement with the value

Energy Resources o70,144 Center predicted by the purely viscous analysis. Energy Resources Center $70,144 Measurements of the dynamic properties

60680 IL ~8Chicago, 01-B including phase shift under oscillatory condition

89-2 are shown to be related to observed heat

Heat Transfer to Aqueous Polbehavior. transfer 

Solutions

J.P. Hartnett

The goal of the research is to study the fluid Jet Propulsion Laboratory

mechanical and heat transfer behavior of California Institute of Technology $105,000

viscoelastic aqueous polymer solutions. The Pasadena, CA 91109 03-C

ultimate objective is to provide a basis for 89-3

predicting the performance of such fluids. At the Neural Learning -Formalisms for Global

present time, two basic investigations are Manipulator Redundancy Resolution

underway: Problems In Unstructured Environments

J. Barhen

a) Pool boiling behavior of aqueous solutions of

several high molecular weight polymers, In many applications the robotic arm needs to

including hydroxyethyl cellulose, have sufficient maneuverability so as to carry out

carboxymethyl cullulose (CMC) and its tasks in the presence of obstacles and in

polyacrylamide and a comparison with pool constricted locations. One way to achieve that is

boiling performance of deionized water. to endow the arm with an extra degree of

freedom. While mechanically that is easy to

b) Forced convection behavior of viscoelastic implement, say by the addition of an extra joint,

fluids in laminar flow through rectangular -the mathematical problem associated with the

channels. guidance of the arm becomes very difficult. The

reason for that is that with the conventional

To date the following results have been found: six-degree-of-freedom system the relationship between the location and orientation of the arm's

a) High concentrations of the aqueous joints and the location of the arm's tip is uniquely

hydroxyethyl cellulose solutions yield higher determined, while the redundancy accompanying

values of the boiling heat flux than found additional degrees of freedom yields an infinity of

with deionized water when compared at the such relationships. The proposed research will

same wall-to-fluid temperature difference. address the resolution of the mathematical

In contrast, aqueous polyacrylamide problems arising in the latter case.

solutions yield lower values of boiling heat

flux than found with deionized water when Specifically, neural networks will be used to

compared at the same wall-to-fluid permit the robot arm to learn which of the

temperature. A new series of measurements possible motions of the arm are the most

with another cellulose (CMC) is underway to appropriate under given conditions. These

determine if this family of polymers has networks are really models of the way we think,

special boiling properties. Detailed leam, and remember. Those functions are

rheological properties are being measured to represented by a set of differential equations with

provide some insight- into the boiling many possible solutions each of which is

behavior. accessible from well defined initial conditions. In

effect the individual solutions serve to encode a

b) The forced convection heat transfer learned response to a given stimulus.

performance of viscoelastic fluids in laminar

flow through rectangular channels is

considerably higher than predicted for purely

Engineering Research 22 1990
Johns Hopkins University Robert H. Kraichnan, Inc.

Mechanical Engineering Dept $67,004 303 Potrillo Drive $59,341

Baltimore, MD 21218 01-C Los Alamos, NM 87544 01-C

89-3 90-3

Numerical and Physical Modeling of Bubbly Turbulence Theory and Reduced

Flow Phenomena Hydrodynamic Description

A Prosperetti R.H. Kralchnan

The ultimate purpose of this study is to put the Turbulent flow is omnipresent in geophysics

widely used engineering averaged-equations and in energy-producing devices. Atmospheric

models of multi-phase flows on a firmer footing turbulent transport plays an essential role in the

by comparing their results with those of direct movement of heat, moisture, and pollutants.

numerical multi-particle simulations and Turbulent flows typically contain an enormous

rigorously-derived averaged equations. amount of information. Both for practicable

computation and for physical understanding, it

Ensemble-averaged equations for the is necessary to extract essential information in

propagation of pressure waves in bubbly liquids compact form. This project explores two recent

have been derived correct to second order in the approaches to economical and meaningful

gas volume fraction. A new insight into the description of turbulence. One is a systematic

structure of the expansion and the role of scheme for reducing the number of degrees of

bubble-bubble interaction and surface freedom ("decimation"). The other, developed

deformations is obtained from the work. only during the past year, is a method for

distorting velocity fields with simple statistics

In a second study, by arranging N bubbles at into self-consistently determined

random in a cubic cell and filling up the entire approximations of actual turbulent velocity

space with copies of this cell, the behavior of an fields ("mapping closure"). Unlike traditional

infinite bubbly liquid has been simulated. For analytical methods for turbulence, mapping

this situation two alternative definitions of added closure yields full probability distributions of

mass have been explored and the average velocity fields and contaminants carried by the

viscous dissipation in the limit of large Reynolds turbulence. In particular, it can give meaningful

number has been studied. estimates of the likelihood of extreme events.

Currently, the application of mapping closure to

In another study, the propagation of pressure the transport of passive contaminants by

waves in a layer of bubbles has been three-dimensional random velocity fields is

considered. The novel feature of this work is the being investigated. Previous work has shown

fact that the volume fraction is arbitrary and the the success of the method for predicting the

wavelength can be comparable to the inter- probability distribution of velocity in Burgers'

bubble distance. model of turbulence.

The last problem involves the flow of a 'plug" of

bubbly liquid in a conduit. For the time being the

bubbles are arranged on the axis of the conduit,

but will later be placed at random.

Engineering Research 23 1990
Lawrence Berkeley Laboratory Lawrence Berkeley Laboratory

Accelerator & Fusion Res Div $123,250 Applied Science Division $194,242

University of California 06-C University of California '06-B

Berkeley, CA 94720 90-3 Berkeley, CA 94720 87-3

Studies in Nonlinear Dynamics Controlled Combustion

AN. Kaufman, R.G. Lttlejohn AIK Oppenheim

This project involves studies of fundamental The principal objective of this project is to

properties of nonlinear dynamical systems which provide a fundamental background for the

arise in physical situations of importance to development of controlled combustion systems.

energy research. A major area of theoretical Of particular interest in this respect are essential

investigation concerns several different aspects improvements of combustors for prime movers

of wave systems. Special focus is given to wave so that they will provide service not only as

packets; the role played by the Maslov index in power sources, to which they are solely

multidimensional wave problems; the occurrence relegated today, but also as modem high-tech

of Berry's phase in wave and other dynamical chemical reactors, where process instabilities

systems; the role of periodic orbits in the and pollutant formation are adequately controlled

spectrum of chaotic wave systems; and linear by a micro-processor system. For automobile

mode conversion. Recent progress includes the engines this offers the prospect ,of efficient and

exploration of the relation between the Maslov clean operation associated with relatively low

index and the phase space structures of exhaust temperature, devoid of the problems of

nonlinear Hamiltonian dynamical systems; new knock and cycle-to-cycle variation and meeting

methods of computing the Maslov index, both for practically all air pollutant emission requirements.

finding wave functions and eigenvalues; The major technological constraints imposed

elucidation of the relationship between the - upon the automotive industry, the octane number

Bohr-Sommerfeld and Maslov phases and the and the catalytic converter, could be therefore

recently discovered "Berry's phase"; a discovery eliminated. Means to accomplish this task

of Berry's phase in the adiabatic motion of involve the utilization of a pulsed jet combustion

charged particles in magnetic fields; a study of system combined with prompt product

complex rays in eikonal theory, and their relation recirculation, according to concepts developed on

to complex Lagrangian manifolds, Stokes' lines this project. Major laboratory apparatus for our

and turning points; a numerical exploration of the studies consists of a cylindrical vessel with

role of periodic orbits in the spectrum of a unobstructed optical insight, and a shock tube

chaotic wave system; and the first treatment of providing about 20 msec of test time at an

mode conversion phenomena for elevated pressure (up to 50 atms) and high

multidimensional systems, involving novel temperature (around 1000K), commensurate with

"reductionn techniques. Emphasis is given to the conditions existing during combustion in engines.

use of a phase space approach to wave Its use is associated with laser-powered optical

phenomena in all these applications. A second instruments, including in particular apparatus for

area of investigation concerns action principles, megacycle-frequency schlieren cinematography

which are being used to imbed single-particle and laser induced fluorescence imagery. In

Le transform perturbation methods in collective addition to experimental work, included in the

models, such as Vlasov-Maxwell systems. program are numerical modeling studies of the

Nonlinear phenomena (e.g., ponderomotive fluid mechanic, thermodynamic, and

forces) are thus dealt with systematically. chemico-kinetic phenomena influencing the

processes of ignition and combustion in engines.

Engineering Research 24 1990
Lovelace Medical Foundation three-dimensional motion and position of the

Bioengineering Research $49,024 camera platform relative to objects in the field of

Albuquerque NM 87108 03-B view. A method has been found that uses a

89-3 robust statistically based calculation to determine

Two-Phase Flow Measurements by NMR the camera motion and feature points in one

E. Fukushima image that correspond to given features in the

other image (stereo correspondence). This

We will use nuclear magnetic resonance (NMR) method is presently being evaluated

to study two-phase flows in model systems. experimentally. Preliminary results from tests

Lovelace Medical Foundation (LMF) will carry out with sythetic images show that the method

the experiments while Sandia National produces accurate results when there are not too

Laboratories (SNL) will provide the theoretical many points without stereo matches in the two

models of multiphase flows as well as help in images, when all the points in the left and right

running the labor-intensive NMR experiments. images belong to objects with th e same threeWe will study steadily flowing nondilute solid dimensional motion relative to the cameras,

suspensions by NMR to obtain the spatial when the noise levels are less than about 10%,

distributions of the phases as well as the velocity and when the cameras are accurately mounted

distributions of each phase. Such determinations in a -parallel configuration. Techniques are

work best under moderately high concentrations currently being developed to extend the method

of both phases, a case that is difficult for light to situations where the four conditions mentioned

and ultrasound scattering. Our exploratory above are not met.

studies for the coming year will include the

following: f) Flow studies of suspensions (heavy

particles in a Newtonian oil) in horizontal tubes to University Of Maryland

determine the dependence of flow properties on Dept of Electrical Engineering $78,600

particle diameter, particle diameter to tube College Park, MD 20742 06-C

diameter ratio, mean particle concentration, 88-4

particle shape and surface roughness, mean flow Study of Magnetostatic Problems in

rate, and relative phase densities; 2) Nonlinear Media with Hysteresis

Measurement of the velocity and spatial LC. Mayergoyz

distribution of a water/oil mixture in the annular

region between counter-rotating, eccentrically- This research is concerned with the development

nested cylinders; and 3) Measurement of the of mathematical models of hysteresis. These

simultaneous, time-averaged, axial velocity models are phenomenological in nature and, for

profiles for two immiscible liquids such as oil and this reason, they can be applied to the

water flowing in a horizontal tube. description of hysteresis regardless of its

physical origin.

University Of Maryland The main research objectives of the ongoing

Dept of Mechanical Engineering $49,999 research can be briefly summarized as follows:

College Park, MD 20742 01-C development of new generalized Preisach

90_3 models of scalar hysteresis, study of new

The Use of Stereo Optical Fow Fields in the Preisach models of vector hysteresis, software

Determination of Three-Dimensional Motion implementation of the Preisach hysteresis

and Stereo Correspondence models, extensive experimental testing and

J.H. Duncan verification of hysteresis models, development of

new techniques for the calculation of magnetic

In this study, the optical flow fields in the left and fields and eddy currents in media with hysteresis,

right image sequences of a stereo camera pair application of Preisach type models to the

are being used to determine the description of

Engineering Research 25 1990
superconducting hysteresis and evaluation of integrity of the signal propagated by the fiber. At

hysteretic losses in hard superconductors. It is present it is not known how much of a limiting

hoped that, as a result of the ongoing research, factor that is for a given statistical distribution of

the foundations of comprehensive theory of the slowly varying inhomogeneities.

mathematical models of hysteresis will be

established. 2. Effects of a varying birefringence. As the

material properties in the fiber change from point

to point so does the fiber's response to the

University Of Maryland polarization of the electromagnetic wave. Under

Electrical Engineering Department $76,091 certain conditions that polarization may be

Baltimore, MD 21228 03-B changed enough by mixing to affect the

89-3 properties of the transmitted signal. Again, while

Pulse Propagation in Inhomogeneous something is known about the effects of a single

Optical Fibers polarization mixing event on a pulse in the fiber,

C. Menyuk nothing is known about the effects of many such

events and how they can be related to the

Many systems, such as computers, sensors for properties of the fiber.

intelligent machines, and high resolution graphics

require ever increasing channel capacity to 3. Bubbles and inclusions in optical fibers.

transfer information from one part of the system Because such imperfections ofen focus the

to another. Recent developments have shown incident electromagnetic beam they are known to

that fiber optics offer a suitable medium to cause damage to the fiber itself. Previous

accommodate the growing need for large data studies have not taken into account the

rates. At present it is not clear how those rates so-called ponderomotive forces, that is body

are limited by the inevitable imperfections in the forces arising from the interactions of the

fibers. This is of particular concern to energy gradients in the properties of the fiber material

systems using this transmission medium because with the incident electromagnetic fields.

the presence of radiation and of other effects

which may affect the integrity of essential This research will address the three topics

communication links in those systems. enumerated above, first in the linear regime and

then in the non-linear regime. While this effort

This research will study the effects of slowly is primarily theoretical, it will benefit from a close

varying inhomogeneities and localized ties to related experimental work at Bell Labs, at

imperfections' in the fibers on their transmission NRL and at FDA.

properties.

Three topics are of particular interest: University Of Maryland

Dept of Mechanical Engineering $64,244

1. Behavior near the zero dispersion point. and Systems Research Center 03-C

This point denotes the frequency at which the College Park, MD 20742 88-3

wave propagation speed is independent of the

wavelength - a point preferred for operating at The Creation of Multl-Degree-of-Freedom

the highest possible data rates because of the Mechanisms for Robotic Applications

lowest power needs. The actual zero dispersion L Tsal

point depends on the material properties as well

as on the geometry of the fiber. Small random This research is concerned with one of the most

variations in those properties along the length of difficult stages of mechanical design, namely the

the fiber will have a destructive effect on the conceptual synthesis of mechanisms. The

objective is to develop a systematic

Engineering Research 26 1990
methodology for the creation of multi-DOF University Of Maryland (Degree-of-Freedom) gear trains for robotic Dept of Mechanical Engineering $122,163

mechanisms. College Park, MD 20742 01-C

87-3

The concept of transmission lines has been Comparative Study of the Vorticity Field in

introduced. Applying the concept, a new Turbulent Flows: Theory, Experiment, methodology for topological synthesis of Computations

articulated gear mechanisms has been J.M. Wallace

established. All admissible structural matrices of

three-DOF gear-coupled robotic mechanisms This is a collaborative project with the City have developed. College of New York and the University of

Houston. Fundamental studies of the vorticity Gear backlash introduces discontinuity, position field in a number of standard sheared and

uncertainty, and impact in mechanical systems unsheared turbulent flows are being carried out.

which, in turn, makes control of a robot difficult. The research involves theoretical, computational

Backlash is a persistent problem due to natural and experimental investigations. clearances provided for prevention of mechanical

interference. Traditionally, precision gears, Theoretically, a mathematical derivation of a

spring-loaded split-gear assemblies, and precise definition of 3-dimensional coherent structures

mechanical adjustments have been used to superimposed on chaotic motion is being

overcome these difficulties. However, these developed with an algorithm to educt these

techniques do not completely eliminate backlash structures. The topological complexity of the

and can further increase the cost of vorticity field and its relation to the basic

manufacturing. processes of spectral energy transfer, vorticity

generation and intermittency will be

In this study, a new and innovative concept for mathematically described in physical space. the control of backlash will be investigated. The

concept utilizes redundant unidirectional drives to Numerically a full Navier-Stokes simulation code

assure positive coupling of gear meshes at all of the turbulent round jet as well as a high times and, therefore, eliminates the backlash resolution code for box turbulence with periodic problem completely. boundary conditions is being developed. With

these codes the coherent structures definitions

A methodology for systematic enumeration of described above will be applied and a detailed

RBR (Redundant-drive Backlash-free Robot) study of energy transfer and helicity fluxes will be

arms has been established and an atlas of conducted.

admissible kinematic structures of two-and

three-DOF, RBR arms has been developed. In Experimentally, the University of Maryland order to establish a proof-of-concept, a planar Turbulence Research Laboratory nine-sensor

two-DOF RBR arm has been constructed, and a hot-wire probe for simultaneously measuring the

controller based on computed torque technique instantaneous velocity and vorticity vector fields

has been designed. It is our plan to do a in turbulent flows has been further developed. comparison study of the arm with and without Point measurements have been made in a

redundant drives. This experiment will be a turbulent grid, mixing layer, and boundary layer

precursor to the investigation of advanced flows in order to obtain properties of the vorticity adaptive control strategies for redundant-drive and helicity fields. Collaborative experiments on

backlash-free robotic arms. turbulent jets and wakes will soon be carried out

at the University of Houston.

Engineering Research 27 1990

2,
The results so far show that there is a higher n ivB ity O ffM sach@utts probability for the velocity and vorticity vectors to Chemical Engineering Dparment ,746 align within the logarithmic region of the Goessmann Labor m aory 03-A

boundary layer and within the mixing layer than Amherst, A 01003-0011 87-3 there would be for two uncorrelated vector fields.

In the buffer layer of the boundary layer and in rning rniv Contrl ruurs for

the grid flow there is virtually no increased Plnt Control System probability for these vectors to align. These J ou1s, .F. alonG

experimental results have important implications

for the prospects of the much disputed This research is focused on developing a more conjecture conjecture that that turbulence turbulence can can be be modelled modelled as as a

a general procedure for the systematic synthesis of Euler flow containing isolated dissipative regions. flowsheets for for chemical processes. These These

procedures are intended to identify the most

important process alternatives, the dominant Rni rSiBty O Mas$schuess $s design variables, and the minimum energy Chemical Engineering Department $ 52,085 consumption for each alternative in processes Amherst, MA 01003-0011 S0-A containing vapor, liquid-liquid and/or solid

88-3 phases. This work will substantially expand Design and Synthesis ?o Reactive process synthesis capabilities, building on earlier

Ssparation Systems results which were the basis of a hierarchical

RF. Doherty synthesis procedure for continuous processes

containing mixed vapor/liquid phases. The design and synthesis of chemical process flowsheets usually begins by breaking the A hierarchy of decisions and rules for the problem down into three main sub-tasks. These synthesis of liquid-liquid separation systems and

are: synthesis of the reactor system, synthesis for crystallizer, filter dryer steps have been of the separation system and the development of developed. The generalized flowsheet structure

an energy management system (i.e. heat has also been identified and an evaluation of the integration). Although these tasks are not interactions with other separation steps is being independent of each other, such a decomposition studied. One important difference between has the advantage of making a very difficult vapor/liquid processes and solids processes problem more manageable. The second stage arises on account of the optimum operating of such a procedure then corrects for temperature for decanters, dissolvers, and mismatches between the sub-tasks. The above crystallizers. The popular energy integration view of flowsheet synthesis can be radically procedures, which have led to major energy altered when the reactions occur in the liquid savings in continuous processes over the last phase. In such circumstances, it is often decade, must be modified to include this possible to combine the reaction and separation unknown temperature. tasks by using reactive separators. Fundamental

studies on the phase behavior, design and Noncontinuous processes which include one or synthesis of this class of problems are proposed. more important batch processing steps are also It is expected that this will lead to a systematic being studied. An algorithmic approach based technique for inventing improved technology and on simulated annealing for the scheduling of that this will be of lasting value to the profession. batch processes including due date and

inventory considerations has been developed and the interactions of the design with the

production schedule are under study.

Engineering Research 28 1990
University Of Massachusetts Massachusetts Institute Of

Chemical Engineering Department $ 75,760 Technology

Goessmann Laboratory 06-C The Energy Laboratory $124,057

Amherst, MA 01003-0011 88-3 Cambridge, MA 02139 03-B

91-3

Mixing of Viscous Fluids: Behavior of Metal Transfer in Gas Metal Arc Welding

Microstructures and Chaos T.W. Eagar, J. H. Lang

J.M. Ottino

The present research is part of a cooperative In spite of its universality and practical program among faculty at MIT and staff at Idaho

implications, the understanding of the National Engineering Laboratory to develop fundamentals of mixing remains rather sensing and control methods which can be used

incomplete. This work focuses on basic to automate the gas metal arc welding experimental and computational studies along processes

two main themes with the objective of

establishing a framework capable of addressing Current research emphasizes understanding of

mixing problems encountered in nature and the forces controlling droplet detachment in gas technology: (1) investigations of chaotic mixing metal arc welding. Experimentally, a laser back

of single fluids in deterministic two- and lit viewing system has been developed which

three-dimensional flows, and (2) dynamics of permits viewing of anode and cathode jet

microstructures in such flows (e.g., stretching, phenomena. Welds have been made with a

breakup, coagulation, etc.). Work in area (1) is variety of different metals teel, aluminum and

underway and a clear picture is emerging. titanium) in different shielding gases (argon,

Experimental work is planned to address the helium, carbon dioxide). It is seen that the

problems listed under area (2). However, most anode spot behavior changes dramatically with

of the results to-date are due to simulation which changes in both metal and gas composition.

focused on coagulation of point particles in

chaotic flows. The particles are convected This experimental information is being coupled

without diffusion and allowed to coagulate with with a model of the forces controlling metal

probability one when their mutual distance is less transfer. These include gravitation, surface

than their diameters. The most significant finding tension, aerodynamic drag, electromagnetic is that under "well mixed" conditions the system (Lorentz) force and plasma jet momentum. Initial

behaves as if the particles were moved by studies show that globular transfer can be

Brownian motion and a simple kinetic model described quantitatively by previous theories

describes the main results. The poorly mixed which were presented originally in only a

case is considerably more complex. In this case qualitative manner. Quantification of previous spatial inhomogeneities result from competition explanations of spray transfer depart markedly

between the rate of coagulation and mixing, and from the experimental observations. A new

trapping and leaking of clusters due to KAM model of the globular to spray transition has

surfaces. been hypothesized and is currently being studied

with a finite element model.

It is believed that this work will ultimately be

useful. in understanding metal transfer in pulsed

current gas metal arc welding. This study also

interfaces with the experimental and theoretical

gas metal arc welding control models being

developed at MIT by Professor D. Hardt and at

INEL.

Engineering Research 29 1990
Massachusetts Institute Of Massachusetts Institute Of

Technology Technology Department of Materials Science $123,110 Energy Laboratory $101,329 and Engineering 06-A Cambridge, MA 02139 03-A Cambridge, MA 02139 91-1 91-3

Synthesis of Heat and Work Integration High Temperature Gas-Particle Reactions Systems for Chemical Process Plants

J.F. Elliot, P.P. Bolsaitis LB. Evans

The purpose of the research is to examine the The goal of this research is to investigate and

physico-chemical behavior of individual inorganic develop improved methodologies for the

particles for conditions simulating those to which synthesis of heat and work integration systems in

particles are exposed during thermal plasma process plants. This is an important problem in

processing. The particle is suspended in a the design of new plants and in the retrofitting of

closed chamber by an electrostatic field, and it is existing plants for energy conservation.

heated by a pulsed laser beam. The

composition of the gas in the reactor can be In a typical process plant, such as a petroleum controlled, and the temperature of the particle refinery, a petrochemical plant, or a paper mill,

can be measured with a time resolution as short many process streams must be heated or cooled

as two-tenths to one millisecond. Equipment for in heat exchangers. The heat integration system optical imaging of the particle during processing recovers heat from streams that must be cooled

is being developed. and transfers it to streams that must be heated.

A plant also requires energy in the form of work

Study is in progress of melting, vaporization, and to drive pumps and compressors and to provide solidification of particles of ceramic materials mechanical energy needed. This work must be (alumina, zirconia), metals (AI-Ni alloys, supplied externally, such as by purchasing aluminum), and carbides (silicon carbide, electricity from a utility, or generated internally WC-Co, and hard facing materials). Methods within the plant. The goal of work integration is

and procedures for improving the accuracy of to identify process modifications that can reduce

single- and two-color temperature the cost of energy in the form of both heat and

measurements during rapid heating and cooling work.

of the particles have been developed.

Measurements have been made of the This project aims to combine powerful evaporation of oxide particles while they are mathematical programming techniques with

heated and cooled. principles of artificial intelligence and include

improved energy integration methodologies so as This work is closely connected with the to develop a user-friendly prototype system for

experimental program on plasma processing at heat and work integration in process plants. the Idaho National Engineering Laboratory, and With this objective in mind, fundamental research

other plasma processing studies in the is being conducted so as to understand the

Department of Materials Science and important parameters involved and their

Engineering at MIT. The combination of data interactions. Algorithms and heuristics are being from this investigation, the data base from INEL developed to synthesize that heat and work

on plasma spraying, and results of modelling of integration system having minimum total cost.

plasma spraying by Professor Szekely's group

(MIT) will provide much more complete

understanding of plasma processing of materials

than has been available heretofore.

Engineering Research 30 1990
The net result of this research will be improved Massachusetts Institute Of

understanding of the nature of the problem of Technology

energy integration in process plants. The

prototype system being developed will help Laboratory for Manufacturing & $152,467

engineers solve realistic industrial problems. Productivity 03-B Cambridge, MA 02139 91-3

Multivarlable Control Of The Gas-Metal Arc Massachusetts Institute Of Welding Process

Technology D.E. Hardt

Dept of Mechanical Engineering $94,668

Cambridge, MA 02139 01-C The Gas Metal Arc Welding Process (GMAW) is

89-3 a highly productive means for joining metals, and

Dryout in Horizontal and Almost Horizontal is being used increasingly for structures and

Heated Tubes pressure vessels. It presents a challenging

P. Griffith multivariable control problem entailing both

geometric and thermal outputs. These outputs

Fluidized bed combustors, waste heat, heat all combine to determine the strength and

exchangers and combined cycle gas toughness of the resulting joint. The overall

turbine-steam turbine power plants all use objective of this work is to examine the problem

horizontal heated tubes with hot gas on one side of simultaneous regulation of all real-time

as the heat source. Because the gas side heat attributes of a weld. Past work has established

transfer coefficient is so low, excessive heat the viability of independent control of thermal

transfer and burnout is never a problem. characteristics, and the present work is

examining the geometric aspects of weld pool

The most important problem is dryout where control.

thermal fatigue or excessive corrosion due to

repeated quenching occurs. Dryout can always One objective of this work is to develop basic

be eliminated by increasing the mass velocity in process modeling and control schemes to allow

the tube but this increases the operating expense independent regulation of the weld bead width

so it is important to know exactly where the and height.

dryout limit is.

A control model relating wirefeed and travel

Previous work has shown that periodic washing speed to width and.height was developed using

and dryout of the tubes in the intermittent (slug transfer function identification techniques applied

flow) flow regime is the most limiting condition. to a series of step welding tests. The resulting

The primary goal of this project is to determine discrete transfer function was found to be nonwhether dryout is due to drainage, evaporation or linear in both the static and dynamic parts, owing

bubble nucleation at the wall. Depending on to a strong dependence upon the input

which mechanism is dominant, a method for magnitudes. This model was then used to

predicting dryout in non-uniformly heated, high develop a decoupling controller design that

pressure, large (2") diameter pipes will be cancels the non-linear behavior using gain

developed and tested. The results will be cast in scheduling. Proper regulation of the process

the form of appropriate boundary conditions for was demonstrated, but the limited range of

a two fluid model of heat transfer in a heated, control afforded by this process, and the

horizontal pipe. significant process delays that were in evidence,

led to very poor disturbance rejection. It is

apparent that the GMAW process will need

significant modifications to overcome these

problems.

Engineering Research 31 1990
In an attempt to merge previous results on the The program consists of experimental and

regulation of thermal characteristics in real-time analytical studies. Experimental work includes

with the geometry control work, we are collection of data on creep properties of the two

developing a control system to independently contacting materials, namely bulk creep behavior

regulate the weld bead width and the width of in tension and interface creep data in shear.

the heat affected zone (HAZ). Initial work is The interface creep takes place when one

concentrating on simulation of wide seam material is pressed against the other by a

welding using an analytical heat transfer model constant force and a shear force insufficient to

as well as a finite difference process model. A produce gross sliding is applied. The extent to

key issue in the problem is the strong coupling which the bulk creep properties determine the

between the inputs (current and travel speed) interfacial creep behavior both at room

and the outputs. The use of high frequency temperature and at cryogenic temperatures will

transverse motion of the torch is being be determined, and this knowledge should lead

investigated as a means of overcoming this to better models of the friction process. In turn,

coupling. Once the control latitude is increased, such knowledge will contribute to a more reliable

a two variable control scheme based on both operation of superconducting magnets.

video and infra-red sensing will be implemented.

Finally, the depth of penetration of a weld is the Massachusetts Institute Of

most important indicator of weld strength, yet it is Technology the one variable that is essentially impossible to

measure directly. A real-time depth estimator Dept of Mechanical Engineering $188,453

has.been developed based on the solution of an Cambridge, MA 02139 01-A

inverse heat transfer problem. Surface 91-3

temperature measurements match the predicted Modeling and Analysis of Surface Cracks

values. Initial experiments with this model, using D.M. Parks, F.A. McClintock

surface temperature measurements from the top

and bottom of the weld, have shown accurate This research focuses on the analysis of ductile

and rapid convergence, and development of a crack initiation, growth and instability in

depth control system based on this estimator is part-through surface-cracked plates and shells.

now proceeding. ' The overall approach consists of careful

calculations of crack front stress and deformation

fields, and correlation of cracking with

Ma.ssachusetts Institute Of experimental observations being conducted at MaSSacusets Institute OU the Idaho National Engineering Laboratory.

Technology

Dept of Mechanical Engineering $66,290 Recently, significant progress has been achieved

Cambridge, MA 02139 01-D in developing and applying a two-parameter

89-2 description of crack front fields. The amplitude of

The Development of a Friction. Model crack tip deformation is characterized by J or

Predicting the Sliding Behavior of Material CTOD, while the hydrostatic constraint in the

Pairs, Especially at Low Temperatures near-tip region correlates well with a parameter

Y. Iwasa' related to the so-called T-stress, or second

elastic Williams' eigenfunction.

The principal objectives of this research program

are 1) to develop a friction model which predicts Simplified engineering applications of surface

correctly whether a system sliding at low speeds crack analysis are being developed in the context

will give steady or unsteady sliding behavior and of the line-spring model. Specific enhancements

2) to advance basic understanding of the friction include improved elastic-plastic procedures for

process. ' the practically important case of shallow surface

cracks, as well as simple methods for calculating

the T-stress along surface cracks fronts.

Engineering Research 32 1990
Massachusetts Institute Of that would inhibit fracture, but this proved not to

~TecAhnn~ologyn~ ~be the case, at least for brittle materials. In Techngnology anticipation of the need for modelling deep The Energy Laboratory $127,845 elastic cracks, an efficient 2-D finite element was

Cambridge, MA 02139 901-A developed that models crack growth as an

91-3 internal parameter within 1%, without

Energetics of Comminution re-meshing. Inhibition from multiple loads may

C. Peterson be of concern for plastic materials, however, and

plastic behavior is of practical significance when

This program is aimed at developing an considering very small particles of any material.

understanding of the behavior of particle beds

under compressive loading and, in particular, the Future work will include preliminary design work

fracture of individual particles within the bed. o a novel crusher concept that integrates

The ultimate purpose is to develop tools to crushing and material transport actions,

permit the design of much more efficient expansion and application of the simulation as a

comminution devices. design tool, more detailed quantitative

experimental work on bed behavior, and further Research is proceeding on four parallel tracks: studies of plastic particle behavior.

analytical and experimental explorations of both

particle bed and single particle behaviors. The

centerpiece of the program is a computer Massachusetts Institute Of

simulation of a two-dimensional bed of

three-dimensional spherical particles, subject to Technology

various moving boundaries and including particle Dept of Mechanical Engineering $107,508

fracture. This simulation is now deemed Cambridge, MA 02139 01-C

satisfactory as a quasi-static design tool and 89-3

examination of potentially improved concepts will Rheological and Flow Characteristics of

begin. This simulation determines forces on and Dense Multiphase Slurries Employing a

motion of all particles, and, in accordance with Bimodal Model

appropriate failure criteria, simulates particle R.F. Probstein

fracture by replacing the failed sphere by several

smaller spheres. The simulation will be The efficient utilization, transport, and handling of

expanded to include fluid dynamic drag on dense multiphase slurries containing high volume

spheres as a means to move material through fractions of solid particles, distributed in size from

the crushing. zone. submicron to several hundred microns, requires

the ability to predict the rheological and flow

Experimental work included measurement of properties as a function of the various physical

force and energy requirements to crush parameters including solids loading, particle

individual small glass spheres (.05 to 1.5 mmin shape and size distribution, stability

diameter) and particle bed studies using roughly characteristics, and solid and fluid properties.

2 mm spheres. Simulated bed behavior Under the grant a rational theoretical and

compares favorably to experimental experimental methodology will be developed for

observations. the rheological and flow property prediction of

dense-phase slurries. The approach models a

Experimental and analytical work on the fracture polydisperse suspension as inherently bimodal,

of large (1 inch) spheres subjected to multiple wherein it is considered to be made up of a fine

point loads has been completed to determine the fraction which behaves colloidally and imparts to

appropriate failure criteria for use in the the suspension many of its important rheological

simulation. There was some concern that many and flow characteristics, and a coarse fraction

loads might induce an hydrostatic stress state which behaves as if it were in a pure liquid with

the same viscous behavior as the colloidal

suspension and raises the apparent viscosity

through hydrodynamic interactions.

Engineering Research 33 1990
The bimodal model has been shown to be. very Massachusetts Institute Of

successful in application to a truly bimodal Tehnol

suspension, where the shear dependent viscosity ecnoo

behavior of the colloidal fraction is determined Dept of Chemical Engineering $52,820

experimentally. For polymodal multiphase flows Cambridge, MA 02139 06-C

the bimodal modeljis being extended, through 88-3

analysis and experiment, to find a rational Los Alamos National

method to divide a continuous size distribution Laboratory2

into a colloidal and a coarse fraction, and to Design Engineering Division $98,600

define the effect of a non-uniform size Aamos, NM 87545 06-C Los Alamos, NM 87545 06-C distribution of each fraction. Additional 88-3

rheological information on the colloidal fraction, Sandia National Laboratories 3

including the effects of the electrochemistry, and S da National

the particle shape and size distribution is also Fluid & Thermal Sciences Dept $98,600

being obtained. Albuquerque, NM 87185 06-C

88-3

Macrostatistical Hydrodynamics

Massachusetts Institute Of H. Brenner', AK. Grahan?, L.A. Mondy

Technology This research aims to establish a link between a

Department of Materials Science $92,806 statistical knowledge of the microstructure and

and Engineering 06-A the macroscopic behavior of dispersed systems,

Cambridge, MA 02139 91-2 such as suspensions of particles in liquids.

Because current capability to predict the behavior

Mathematical Modelling of Transport of multiphase systems is limited, this

Phenomena in Plasma Studies fundamental knowledge of suspensions will

J. Szekely benefit a host of technologies, especially related

to geothermal energy production, petroleum

The purpose of this investigation is to develop a production and refining, and synfuels processing.

comprehensive mathematical representation of Current empirical design procedures in these

heat flow, fluid flow and mass transfer technologies are deficient in understanding how

phenomenon in thermal plasma systems and to overall system behavior is related to the system's

compare the theoretical predictions with micromechanics.

experimental measurements.

The approach to enhancing this understanding -

A general formulation of the problem has been involves a novel combination of experiments,

developed and an extensive set of computed numerical calculations, and theory. Real-time

results has been generated, describing the radiography, high-speed video, and image

velocity profiles, temperature profiles and processing are being used to observe and record

concentration .. profiles in a' variety of the motions of spheres as they settle through

non-transferred arc systems. The theoretical suspensions of particles. Measurements of the

prediction were found to be in good agreement- average and higher moments of the position and

with measurements reported by researchers at velocity distributions of the tracer sphere will

the Idaho National Engineering Laboratory and in provide the boundary conditions for computer

two University Laboratories. More recent work is simulations of the flow fields in the continuous

concentrating on plasma-particle interactions phase surrounding individual particles. This

and on transport phenomena inside plasma statistical knowledge of the mechanical response

torches. This latter work is very promising in of both disperse and continuous phases will then

providing a rational science base for plasma be the basis for the development and verification

torch design. of a new theory for predicting overall macroscale

mechanical response of multiphase systems.

Engineering Research 34 1990
To date, experimental measurements of the University Of Minnesota

three-dimensional position versus time of tracer Dept of Aerospace Engineering $ 68,000 spheres settling in quiescent suspensions have and Mechanics 01-C

shown that the settling velocity varies more in the Minneapolis, MN 55455 90-3

direction parallel to the fall than in the

perpendicular direction. Therefore hydrodynamic Stability Studies of Core-Annular Flows

dispersivity must be represented as a tensorial DD Joseph

rather than scalar quantity. A theory has been

developed to relate the average velocity of a The objectives are to understand and control

tracer to the macroscopic viscosity of a drag reduction in water lubricated pipelines and

suspension, including effects of container to determine condition sof stability in water film

boundaries. Finally, both the finite element and cooling of water vapor (with phase change) for

boundary element methods have been used to possible application to nuclear safety. We have model the hydrodynamic interactions of up to 25 developed a successful linear theory for suspended particles. predicting regimes of lubricated flow.of oil and

water and we have new experimental results in

lubricated flow in vertical pipes. We are now University Of Minnesota doing nonlinear theory and preparing

Dept of Mechanical Engineering $113,676 experiments on water lubricated pipelining of

Minneapolis, MN 55455 01-B coal-oil dispersions. We are generally supported

87-4 and encouraged by Shell Development in

The Impact of Separated Flow on Heat and Houston and are world leaders in this subject.

Mass Transfer We are going to apply the methods we use for

R.J. Goldstein water lubricated pipelining to nuclear safety, but

we don't know how it will turn out.

In many real flow systems separation occurs

either intentionally or unintentionally. Such

separations, often unsteady by nature, tend to University Of Minnesota

result in three-dimensional and secondary flows. Dept of Mechanical Engineering $129,723 Heat and mass transfer in some situations can Minneapolis, MN 55455 06-C

be unsteady; there can be energy separation in 88-3

the flow and often large gradients in heat and/or Thermal Plasma Processing of Materials

mass transfer occur which are difficult to E. Pfender

measure. The proposed study will include a

variety of flow situations involving separation and For measuring temperature and:velocity fields in

also the development of special measurement plasma systems used for thermal plasma techniques to study the heat and mass transfer processing, enthalpy probes have been

in the presence of large gradients. Situations to developed and tested in this laboratory. The

be studied include the flow over two and validity of measured enthalpy and velocity three-dimensional steps, separation of the flow profiles has been checked by performing energy around circular and square cylinders projecting and mass flux balances in an argon plasma jet from surfaces including the influence of a operated in argon atmosphere.' horseshoe vortex and localized fins, flow through

a porous medium represented by a simple flow, Ceramic powders of carbides, aluminum' nitride, and the vortex rings formed around a jet as it oxides, solid solutions, magnetic and nonflows out of an orifice.or nozzle. These include magnetic spinels, superconductors, and

the development of precision microsensors for composites have been successfully synthesized highly localized measurements of the heat flux, in a Triple DC Torch Plasma Jet Reactor (TTPR) and further development of techniques for local and in a single DC Plasma Jet Reactor. All the

mass transfer measurement. ceramic powders with the exception of AIN were

Engineering Research 35 1990
synthesized using a novel liquid injection method Experiments have been performed with

developed to overcome the problems associated downward flow of water in a packing of uniform

with solid injection, in particular for the single DC diameter, poured, glass spheres with a vertical

plasma jet reactor, and to realize the benefits of temperature gradient. The transition of the flow

gas phase reactions. structure has been observed for a range of

temperature gradients characterized by a

Equilibrium calculations based on the standard Rayleigh number, and different flow rates

technique of minimization of the system total characterized by a thermal Peclet number. The

Gibbs free energy are not adequate for transition to mixed forced-free convection is not

predicting the yield and the proper composition abrupt as would be predicted from the volumeof the products from thermal plasma systems. averaged equations of motion and energy.

This is due to domination by nucleation kinetics, Instead, the flow structure undergoes

a non-equilibrium effect. Therefore, total Gibbs distributions which indicate a random structure

free energy minimization calculations using a which gradually changes to approximate modes

quasi-equilibrium modification have been applied determined from the confining geometry.

to, for example, AIN, ZrC and MgAI20 4 reactions. Dispersion obtained from the standard deviation

The modeling results agree well with of dye transit times at the plane of observation

experimental data in terms of product yield and shows a generally increasing trend, with a small

composition. maximum preceding the occurrence of circulating

(free convection) flows. The interpretation of

these observations is aided by numerical solution

National Institute Of Standards of the governing equations for grids with

And Technology randomly distributed porosity. These show similar precursors to circulating flow associated

Chemical Eng Science Division $104,170 with neutrally buoyant stagnant regions of the

Center for Chemical Technology 01-C bed

Boulder, CO 80303-3328 89-3

Convection and Dispersion in Coarse-National Institute Of Standards

Packed Beds

M.C. Jones, J.D. Wolfe And Technology

Thermophysics Division $509,486

One of the most widely used items of industrial Gaithersburg, MD 20899 03-B

equipment is the packed bed in which, Boulder, CO 80303 90-5

commonly, a vertical throughflow exists through

a packing which is relatively coarse. The Thermophysical Property Measurements in

presence of temperature or compositional Fluid Mixtures

gradients in conjunction with the stochasticity of R.F. Kayser, J.M.H. Levelt-Sengers

the packing on the scale of observation leads to

flow structures which may be hard to predict but The project aims at the development of accurate

which are, in any case, not uniform. The flow measurement capabilities for the thermophysical

structures observed under these conditions are properties of complex, multiphase, fluid mixtures

being studied with the, aid of an array of containing hydrocarbons. The research is being

fiberoptic probes which detect the concentration done jointly by two research groups within the

of a fluorescent dye injected with the Thermophysics Division of the NIST Center for

throughflow. This technique allows time- Chemical Engineering. One group is located at

resolved imaging of the flow structure in the the Gaithersburg, MD laboratories and the other

plane of the array. Considerable insight into the at the Boulder, CO laboratories. The properties

state of convection may be obtained from some involved are PVT (pressure-volumeof the statistics available from individual probe temperature), PVx (pressure-volumeresponses. These include the residence time composition), phase equilibria (liquid-vapor and

distribution, the spatial distribution of transit liquid-liquid equilibria), phase behavior in

times, and their means and standard deviations. interfaces, and transport properties (viscosity,

Engineering Research 36 1990
thermal conductivity, and diffusion coefficient). The initial phase of this program is to determine

The apparatus will be designed for use in the compatibility of various metals and alloys (Au

corrosive, highly corrosive, and sometimes toxic and Al alloys and W, for example) as contact

and flammable fluids with measurements materials for superconducting YBCO and other

extending to high temperatures (800K) and high high T= materials. Once a good combination has

pressure (30 MPa and in some cases 70 MPa). been established, patterned YBCO\normal metal

Also under study are methods for evaluating contacts will be deposited onto semiconductor

supercritical solvent mixtures and related fluid wafer surfaces. We have purchased a sputter

mixtures. co-deposition system for YBCO thin films and

have adapted three other vacuum systems for

The most recently completed apparatus include contact deposition including two sputtering

a variable volume vapor-liquid equilibrium systems and an evaporator.

apparatus for moderate temperature ranges; a.

Langmuir film balance for use with aqueous,

hydrocarbon, and biopolymer systems; a The City University of

magnetic suspension densimeter for high New York

temperatures and pressures; a torsional crystal w

viscometer for high temperatures and pressures; The City College $162,982

and a transient hot-wire apparatus for thermal The Benjamin Levlch Institute 01-C

conductivity measurements at high temperatures. for Physico-Chemcal Hydrodynamics 90-3

The latter two apparatus are capable of reaching New ork, N 10031

pressures near 70 MPa. The Rheology of Concetrated Suspensions

A Acrivos

National National Institute Of Of Standards Standards This research program aims to investigate the

And Technology flow of concentrated suspensions from a

Superconductor & Magnetic fundamental point of view. Earlier studies by the

Measurements Group $94,700 principal investigator and his associates have

Electromagnetic Technology Division 06-C uncovered two effects which exert a major

Boulder, CO 80303 89-3 influence on the rheology of such systems even

under conditions when the particle Reynolds

Low Resistivity Ohmic Contacts Between numbers are vanishingly small, specifically: a)

Semiconductors and High-T, the shear-induced migration of particles from

Superconductors regimes of high shear to low, and from regions of

J. Moreland, J.W. Ekin high concentration to low, and b) the

resuspension of a settled bed of particles when

The purpose of this project is to fabricate and subjected to shear.

characterize high-T= superconductor/

semiconductor contacts. Developing a method Both these effects are currently being studied

for optimizing the current capacity of such experimentally in a double-gap Taylor-Couette

contacts will extend the application of high-T= apparatus where it is has been found that a

superconductors to hybrid superconductor- settled bed of glass beads in a viscous fluid

semiconductor technologies. These technologies resuspends under the action of shear. In fact,

include integrated circuit interconnects (both on- the settled bed completely resuspends and

chip and package) and proximity superconductor/ particles are seen to migrate from the chamber

semiconductor/superconductor SNS Josephson having the lower shear rate to the other, in

junctions. Presently, these are among the most quantitative agreement with an existing

promising high-T. superconductor applications, theoretical model.

but an essential first step is the development of

reliable, stable, ohmic contacts between

semiconductors and the high-T, oxide

superconductors.

Engineering Research 37 1990
The City University Of A method of creating initial field for simulations of

New York decaying turbulence has been developed which

The City College $122 enables creation of Gaussian velocity field with The aCity College c i$122,1u63 given energy and helicity spectrum. It has been

The Benjamin Levich Institute 01-C shown in numerical experiments that strong for Physico-Chemical Hydrodynamics 87-3 for 87-3 helicity slows down the cascade of energy and

New York, NY 10031 the buildup of enstrophy at all later times.

Comparative Study of Vorticity Field in

Turbulent Flows

E. Levich The City University Of

New York The purpose of this project is to study - Nw

theoretically, numerically, and experimentally The City College $60,750

coherence in vorticity field. During the last year Department of Chemical Engineering 01-C

the following results have been obtained. New York, NY 10031 87-3

The analysis of the build up of coherence in Periodically Structured Multiphase Flows

numerical isotropic turbulence has been and Hydrodynamic Instabilities in Narrow

performed. Large fluctuations of helicity and the Channels

growth of helicity at low scales been has C.M. Maldarell

detected in 128 x 128 x 128 simulations of decay

turbulence. The goal of this research effort is to understand

the hydrodynamics and stability of fluid particle

The comparative study of symmetry breaking in multiphase flows in capillaries (e.g., the

turbulence has been considered. It has been movement of foams, emulsions, and gas and

shown that in order to preserve statistical liquid slugs). Particularly encouraging and

invariant the continuous growth of coupling H(k) significant progress has been obtained on the

H(k') is inevitable. Laboratory experiments with influence of surface active agents on these flows.

two different systems - water past the grid and

air past the grid - support this observation. In Surfactant molecules adsorb onto a fluid particle

both experiments helicity spectrum has been surface, and are convected to the back end of

measured and the build up of coherence was the particle. If the desorption and bulk diffusion

observed. of the surfactant away from the surface is slow

compared to the convective rate of transport to

A theoretical model of the phase coherence in the back end, surfactant accumulates and

turbulence observed in numerical simulations of creates Marangoni stresses which retard the

turbulence and laboratory experiments has been surface velocity. In the context of the movement

constructed. A stationary driven turbulence, was of fluid particles in narrow pores, the

reduced to a 4-D equilibrium system. immobilization of-the particle interface increases

the pressure drop required to move the flow

The study of the linear stability of incompressible regime and thus lowers the mobility of the

turbulent fluids with respect to coherent particle phase.

perturbations which give a nonzero mean flow

has been performed. It was shown that there' is By undertaking experiments on a particular slug

no instability, in marked contrast to the flow regime in a capillary, this investigation has

compressible case, where the compressible reflectional reflectional identified non-retarding polyethoxy surfactants.

asymmetry of the basic turbulence rendered These surfactants have in common two

certain helical perturbations unstable. characteristics: First, their desorption kinetics is

fast. Second, at elevated bulk concentrations,

they form micelles which can quickly exchange

Engineering Research 38 1990
with monomer in free solution. This latter technique for solving the relevant mathematical

characteristic increases the rate of bulk diffusion problems. This approach enables one to reduce

of monomer away from the surface as the the study of complex physico-chemical systems

micelles act as monomer 'sinks." Since the governed by strongly nonlinear,

transport away from the surface is unhindered, three-dimensional and highly coupled sets of

these surfactants do not collect at the back end partial differential equations to the incomparably

of the particle, and no Marangoni stresses more simple weakly nonlinear evolution

develop. equations of lower space dimensions. These

equations are then easily tractable either

This investigation has also demonstrated how analytically or numerically. With all their relative

nonretarding surfactants can be used to simplicity the reduced equations proved rich

remobilize a surface previously retarded by the enough to capture many nontrivial features of

adsorption of a surfactant impurity unavoidably physical systems which hitherto resisted

dissolved in the bulk phase. When the fluid analytical description by any other means.

particle phase is formed, the polyeythoxy Specifically, in this study multiple-scale methods

surfactant, present at high concentration in the are applied to the mathematical modelling of

bulk, preferentially adsorbs onto a surface, not curved nonsteady flames propagating in gaseous

allowing adsorption of the impurity and combustible mixtures. A nonlinear geometrically

maintaining a mobile interface. This concept of invariant dynamic equation for the flame front

remobilization has applications in many areas, evolution is derived on the assumption that the

particularly in microgravity separations where curvature of the flame is small. The equation

thermocapillary induced migration can be generalizes the corresponding weakly nonlinear

reduced considerably by the presence of equation obtained previously near the stability

surfactant impurities which retard the surface threshold. The new equation is capable of

mobility, and in foam drive oil recovery where the describing the evolution of complex geometric

use of remobilizing surfactants can lead to flame configurations such as those frequently

greater control on the mobility of foam in rock observed in a strongly turbulent gas flow.

pores.

A theory of chaotic, hexagonal and polyhedral

spinning flames is developed. Effects of

The City University Of acceleration on flame propagation in horizontal,

New York vertical and rotating channels are analyzed.

The City College $94,700 The concept of turbulent flame speed based on

The Benjamin Levich Institute 06-C invariant renormalization group approach is

of Physico-Chemical Hydrodynamics 87-3 proposed. A consistent mathematical theory of

New York, NY 10031 premixed flame propagating in large-scale

homogeneous turbulent flow-field is elaborated. Topics in Physico-Chemical An equation for turbulent flame speed as a

Hydrodynamics function of the turbulent flow-fieldintensity is G.I. Sivashinsky derived.

The objective of this project is a unified The study is presently in progress of

theoretical approach to the description of spontaneous formation of large-scale structures

large-scale spatio-temporal structures in thin liquid films, in interfaces under directional

spontaneously emerging in a variety of solidification, and in viscous flows performing physico-chemical systems. periodic motion at small scales.

The significant difference between the

characteristic scales of the primary and

secondary structures suggests the method of

multiple scale asymptotic analysis as a natural

Engineering Research 39 1990
North Carolina State University Northwestern University

Department of Mechanical $91,859 Department of Civil Engineering $80,921

and Aerospace Engineering 06-A Evanston, IL 60208 03-B

Raleigh, NC 27695-7910 89-4 89-3

Effects of Crack Geometry and Near-Crack

Transport Properties Of Disordered Porous Material Behavior on Scattering of

Media From The Microstructure Ultrasonic Waves for QNDE Applications

S. Torquato J.D. Achenbach

This research program is concerned with the A crack in a solid body can, in principle, be

quantitative relationship between transport detected and characterized by its effect on an

properties of a disordered heterogeneous incident pulse of ultrasonic wave motion.

medium that arise in various energy-related

problems (e.g., thermal or electrical conductivity, The work on this project is concerned with

trapping rate, and the fluid permeability) and its applications of the scattered field approach to

microstructure. In particular, we shall focus-our the detection and characterization of cracklike

attention on studying the effect of: porosity, flaws. The work is both analytical and

spatial distribution of the phase elements, numerical in nature. Several forward solutions

interfacial surface statistics, anisotropy, and size to model problems have proven to be very

distribution of the phase elements, on the helpful in the design of experimental

effective properties of models of both configurations. They are also valuable in

unconsolidated media (e.g., soils and packed interpreting scattering data for the inverse

beds of discrete particles) and consolidated problem.

media (e.g., sandstones and sintered materials).

The efficacy of ultrasonic methods to detect

Both theoretical and computer-simulation and characterize a crack depends on

techniques have been employed to quantitatively topographical features of the crack faces, the

characterize the microstructure and compute the presence of inhomogeneities in the crack's

transport properties of disordered media. environment, and on the mechanical properties

Statistical-mechanical theory has been used to in the near-crack region. In this work the

obtain n-point distribution functions and to study effects on the scattered ultrasonic field of

percolation phenomena in continuum various features of fatigue and stress corrosion

random-media models. This has led to accurate cracks, such as partial crack closure, the

predictions of transport properties of realistic presence of microcracks and microvoids, and

models of isotropic as well as anisotropic near-tip zones of different mechanical

heterogeneous media. An efficient properties have been investigated. Most of the

computer-simulation methodology has been results have been obtained by formulating a set

developed to exactly yield effective transport of singular integral equations for the fields on

properties in which the transport process is the boundaries of the scattering obstacles.

governed by a steady-state diffusion equation. These equations have been solved numerically

Hence, the algorithm, which is based upon by the boundary element method, and the

simulating the Brownian motion of a diffusing scattered fields have subsequently been

particle, can be applied to determine the obtained by using representation integrals.

conductivity, dielectric constant, magnetic

permeability, diffusion coefficient, and the For the configurations examined in this work,

trapping rate associated with diffusion-controlled crack closure has the most significant effect on

reactions among sinks. far-field scattering.

Engineering Research 40 1990
Northwestern University For viscous liquids the temperature dependence

Department of Engineering Sciences $ 0 of viscosity may also be important, leading to

and Applied Mathematics 01-B another dimensionless parameter. It is shown

Evanston, IL 60208 89-3 that, by rescaling, the new results can be

expressed in the same form as the WilliamsThinning And Rupture of a Thin Liquid Film Davis equation. The theory is generalized to the

on a Horizontal Heated Solid Surface case of a two-component liquid simultaneously

S.G. Bankoff, S.H. Davis evaporating and draining on a horizontal spinning disk, as in photolith production. A region of

A thin liquid film on a horizontal heated plate can transient stability is found, especially for poor

become unstable and rupture, exposing dry solvents of high volatility, which can lead to

areas of the plate. frozen-in surface waves-in the finished polymer

film.

For a volatile liquid we analyze the

consequences of evaporation on the layer,

incorporating the effects of viscosity, surface Northwestern University

tension, vapor recoil, thermocapillarity and

long-range molecular (van der Waals) forces in Department of Engineering Sciences $49,007

a nonlinear stability theory for the film. We have and Applied Mathematics 01-C

also extended the theory to include the effects of Evanston, Illinois 60208 88-3

a non-volatile solute on the stability of the

evaporating film. Quite general forms of the Attenuation of Waves in Partially Saturated

viscosity-concentration function can be Porous Solids

employed. - M.J. Miksis

If the liquid is non-volatile, and a This project will be concerned with investigating

two-dimensional heating strip is inlaid in the the dissipation of energy associated with the

plate, thermocapillarity creates a dimpled motion of fluid in a partially saturated material.

interface. As the heat flux to the strip increases, An understanding of this process is important in

the dimple deepens until dryout occurs. A explaining the attenuation of waves

nonlinear theory for this steady state and its (compressional and shear) in a partially

instabilities is given, in which we include the saturated porous material. It is also important in

effects of viscosity, surface tension, understanding how two immiscible fluids (e.g. oil

thermocapillarity and van der Waals forces. and water) displace one another in a porous

media. On the microscopic scale we will allow

In the latter case we examine experimentally the the fluid to dissipate energy by viscosity and by

dimpling of an oil film and compare quantitatively the movement of the contact line of the

the interface profiles measured and predicted, gas/liquid/solid intersection. There are two parts

giving the temperature profiles sensed with of this project. The first concerns an

thermocouples. Excellent agreement is obtained, investigation of the fluid mechanics associated

giving the first experimental confirmation of with contact line movement, while the second

lubrication theory applied to these films. concerns using these results in either existing or

modifications of existing macroscopic theories of

When the heated plate is tilted with respect to wave propagation in a porous material.

the horizontal, a heated falling film is created.

The former theory is generalized to examine the The first phase of this project is currently

interplay between the bulk flow and evaporative underway. A macroscopic theory of wave

effects. Wavebreaking, sideband instabilities, propagation in partially saturated porous media

and thinning to the point of dryout are studied, which includes the effects of contact line

using asymptotically-correct approximations. movement has been developed. There are

several limitations on this model but it does show

Engineering Research 41 1990
that there can be considerable error in first subharmonic. Also observed are side band

attenuations if contact line movement is interactions, which promote transfer of energy to

neglected especially for low frequency waves. low frequency modes (of possible importance in

The motion of the fluid in this model was solved slug formation), and emergence of disturbances

for analytically by matching. In order to better transverse to the flow direction. To interpret the

understand this model and the effects of the measurements, a set of weakly-nonlinear waves

contact line motion on the fluid motion we are approach is reasonable because' experiments

currently developing a numerical code to solve indicate that waves usually saturate with wave

the microscopic moving boundary problem. slopes less than 1/50.

Initially a lubrication model is being investigated.

Next we plan to consider the complete equations It is expected that identification of the generic

of motion and to systematically incorporate these behavior close to neutral stability will aid' in

results into a macroscopic model of waves in interpretation and prediction of wave spectra at

partially saturated porous materials, more highly-sheared conditions.

University Of Notre Dame Oak Ridge National Laboratory

Department of Chemical Engineering$49,194 Engineering Physics $1,270,878

Notre Dame, IN 46556 01-C and Mathematics Division 03-C

88-3 Oak Ridge, TN 37831 87-5

Study of Interfacial Behavior in Cocurrent

Gas-Liquid Flows Center for Engineering Systems Advanced

M.J. McCready ,Research (CESAR)

R. Mann

The objectives of the work are to 'develop an

understanding of the fundamental behavior of The Center for Engineering Systems Advanced

interfacial waves which occur in separated Research (CESAR) conducts interdisciplinary, -

gas-liquid flows. Interfacial waves influence long-range research and concept demonstration

significantly pressure drop, transport rates, related to intelligent machines. CESAR provides

atomization and flow regime stability; however, a framework for merging concepts from the fields

accurate methods for predicting this behavior are of artificial and machine intelligence with

not presently available, advanced control theory. There are two primary

themes: (1) robotics systems for identification,

The primary focus this year has been flow navigation, and manipulation in unstructured

conditions very close to neutral stability. This environments, and (2) multi-purpose plant

was chosen because specific aspects of wave management for maintenance.

behavior are easily identifiable. Experiments

show that a mode corresponding to the linearly Illustrative FY 1990 research initiatives resulting

most unstable-wavelength grows first followed in archival publications have included: (1)

immediately by one or more overtones.. Because Concurrent Simulation: Development and

the overtones are linearly stable- and are Testing of a Learning Expert system for an

coherent in phase with the fundamental mode Autonomous Robot, (2) Autonomous Mobile

(as determined from bicoherence spectra) they Robot Navigation and Learning, (3)

are probably generated by nonlinear interaction Asynchronous Production Systems for Control of

with the fundamental mode. This net energy an'Autonomous Mobile Robot, (4) HERMIES-III:

transfer to stable modes is the primary A step Toward Autonomous Mobility Manipulation

mechanism by which linearly unstable modes and Perception, and (5) Treatment of Systematic

saturate at finite amplitudes. If the fundamental Errors in the Processing of Wide Angle Sonar

mode saturates at a sufficiently large amplitude, Sensor Data for Robotic Navigation.

it is possible for energy to be transferred to the

Engineering Research 42 1990
In addition, CESAR organized a national Advanced bioreactor/biosorber concepts -

workshop and published Proceedings of the Fixed- and fluidized-bed bioreactors and/or

1989 Workshop on Human-Machine Symbiotic biosorbers using immobilized bioreagents are

Systems. Finally, the HERMIES-III robot advanced concepts that have the potential for

assembly has been completed and quality significantly increasing productivity. However,

assurance/safety procedural testing is underway. such systems are not well defined, since they

may contain three or four interacting phases,

including a changing gas phase. The coupling of

Oak Ridge National Laboratory hydrodynamics, gas generation or depletion,

Chemical Technology Division $98,600 gradients of phase fractions, and biokinetics in

Oak Ridge, TN 37831 - 06-A continuous columnar systems will be investigated

89-3 and predictive mathematical models will be

Bioprocess Engineering Research for developed.

Energy ApplicationsC.D. Scott

Ohio State University This program will support engineering research Physics Department $63,733

in three primary areas that 'are critical to an Columbus, OH 43210 03-B

expanding use of advanced bioprocessing 88-3

systems for energy production and conservation: Physics of Cellular Automata and

(1) efficient biocatalytic systems, (2) advanced Coherence and Chaos in Many-Body

bioreactor concepts, (3) innovative Dynamical Systems

bioseparations approaches. C. Jayaprakash, F. Hayot

Efficient biocatalytic systems - Several advanced This program deals with the dynamics of

bioreactor concepts require that the biological non-linear systems. It concerns two significant catalyst (microorganisms or active fractions) be areas of research:

retained in the bioreactor at high concentrations

in a microenvironment that enhances biological (i) the study of automata both as microscopic

activity. A fundamental understanding of the models underlying the macroscopic physics

basic kinetics and dynamics of such biocatalyst embodied in partial differential equations, and, in

systems and a predictive mathematical model will their own right, as simple, non-linear dynamical

be developed, -systems exhibiting complex behavior.

Innovative bioseparations approaches - (ii) the study of spatial coherence and temporal Advanced separations concepts will be needed chaos in systems with many degrees of freedom:

to isolate or concentrate the dilute aqueous as model systems, couple maps on

components of bioconversion systems or waste d-dimensional lattices will be investigated.

streams from energy processes. The research

emphasis will be on separation concepts that

utilize solid-fluid interactions with an initial study

of the use of biological materials (certain

microorganisms and plant and animal tissue) as

bioadsorbents for the isolation and concentration

of dissolved metals.

Engineering Research 43 1990
University Of Pennsylvania Physical Optics Corporation

Electrical Engineering Department $104,312 2545 W. 237th Street, Suite B $148,674

Philadelphia, PA 19141 03-B Torrance, CA 90505 03-B

88-3 89-3

Interaction of Radiation with Surface Nonuniform Uouville Transformers for

Microstructures Quasi-Homogeneous Optical Fields

J. Zemel J. Jannson

Recent theoretical and experimental studies have In this program, Nonuniform Liouville

shown that the basic approach leading to the Transformers (NLT) are proposed for an

conventional views about the nature of black important class of quasi-<R>homogeneous

body radiation fails when the size of the cavity is optical fields containing those emitted by thermal

comparable with the wavelength of the incident (Lambertian) and other convectional sources, as

radiation. Such a situation can arise when light well as by the majority of multi-mode

interacts with periodic microgrooves inscribed on high-energy (CO2, Nd:YAG, Excimer, X-ray,

a surface. The detailed nature of such an etc.) lasers and semiconductor lasers (including

interaction may be studied by means of spectral, laser diodes (LD), which are important sources in

angular, polarized emittance (SAPE). local area networks (LANs)). These NLTs are

nonuniform, nonimaging beam-shaping systems

Preliminary results show that SAPE allows the acting on the basis of the general energy

measurement of.the effects of thermally excited transport equations for the phase-space density

standing waves in the microgrooves on the (related to the generalized Uouville theorem) and

scattering of the incident radiation. It was found the power flux vector. The proposed theoretical

that indeed there are standing waves in the model is more general than those based on

interior of the microgrooves, or slots. Those geometrical optics (including Winston's

waves couple efficiently to the incident radiation nonimaging optics), yet less general than those

as well as to the. surface plasmons. The based on either the scalar diffraction or

measured dependence of the latter coupling electromagnetic theory. The fundamental goal of

onthe depth of the slot cannot be accounted for this program is to find a theoretical and

fully by the existing theory. Measurements of the engineering solution for highly efficient (close to

radiation scattered by the microgrooves shows 100%) beam shaping/concentration/ collimation

that spontaneous emission is inhibited in some of weakly spatially coherent and quasi-uniform

directions. It is possible that this unusual large-aperture optical fields (so called

behavior may find eventually practical quasi-homogeneous fields, which are more

applications in electro-optic devices. general than Lambertian ones), using an

optimized higher-hierarchy architecture of

This research program call for determining how longitudinal and transversal, imaging and

the geometry of the microgrooves affects the nonimaging optical elements (nonimaging cones,

interaction between the incident radiation and the lenses, diffusers, holographic optical elements

standing waves inside the slots; determining the (HOEs)). 'The proposed theoretical model holds

role played by the material properties of the for the quasi-homogeneous radiation emitted by

micromachined surfaces on the polarized, the state-of-the-art of the majority of high

angular emission; and determining the necessary energy and coherent and noncoherent

corrections to the Stefan-Boltzman radiation law electromagnetic sources.

necessitated by the small size of the scattering

cavities.

Engineering Research 44 1990
Physical: Sciences Inc. (0.4 nm radius) which then grow in a number20 New England Business Center $118,375 conserving fashion. This work shows that

Andover, MA 01810 06-A nucleation and condensational growth do not

88-4 occur in separate stages beginning at onset, and

Experimental and Theoretical Studies of it establishes both the presence and importance

Condensation in Multicomponent Systems of large droplets at the onset of condensation.

M.B. Frish, G. Wilemski

This research program comprises experimental Princeton University

and theoretical studies of nucleation and Department of Mechanical $91,859

condensation- in multicomponent gas mixtures. and Aerospace Engineering 06-B

The program 'goals are: (1) to improve basic Princeton, NJ 08544 90-3

understanding of nucleation and droplet growth,

(2), to stringently test theories of nucleation at Mechanisms and Enhancements of Flame

high nucleation rates and under nonisothermal Stabilization

conditions, (3) to develop improved theories C.K. Law

where needed, (4) to enlarge the data base for

systems of both fundamental and practical The program aims to gain fundamental

interest, and (5) to provide reliable means for understanding of the structure and stabilization of

predicting the behavior of mixtures used in premixed and diffusion flames through theoretical

practical' applications such as turbo-machinery. and experimental investigations. Several

Experimentally, condensible vapors mixed with a projects were completed during the reporting

carrier gas are cooled in a supersonic nozzle to period.

obtain high nucleation rates. The nozzle is

designed to ensure that steady-state nucleation A theoretical analysis has been conducted on the

occurs and to give satisfactory spatial resolution structure and extinction of diffusion flames with

of the temperature profile. Laser'light scattering flame radiation. The structure analyzed consists

and interferometry are used to detect the "onset" of a thin reaction zone embedded within a thicker

of condensation and to monitor subsequent radiation zone which in turn is situated within the

droplet growth. 0(1) diffusive-convective flow field. Using

.- ~ ...- ~droplet ~ combustion as a model problem, the

Experiments on 'condensing water vapor have recent analytical results exhibit a dual extinction

shown that the number density of water droplets behavior in that flame extinction occurs not only

falls sharply after an initial rapid increase. This for sufficiently small droplets due to reduced

previously unobserved behavior appears to be residence times, as is well established, but it also

due 'to' polydispersity of: the droplet size occurs for sufficiently large droplets as a result of

distribution which favors growth of larger droplets excessive heat loss from the correspondingly

at the expense of smaller ones. Theoretical large flame. Consequently there exist systems

calculations of the droplet size distribution along for which steady combustion is not possible for

the flow axis 'support this interpretation. The all droplet sizes.

calculated size distribution broadens rapidly;

large numbers of large droplets (9 nm radius) are A theoretical and experimental investigation has

already present at the observable onset of been performed for the effects of flame curvature

condensation. The rapid growth in-number and on diffusion flame extinction by using opening of

size of these large droplets is responsible for the the Burke-Schumann flame tip as the model

latent heat release that disturbs the gas flow. problem. Asymptotic analysis of the flame

These results contradict the conventional view of structure in the tip region shows that increasing

condensation in nozzles. In that view, onset is the extent of the flame curvature facilitates nearattributed to the rapid nucleation of a complete reaction and thereby enhances the

monodisperse cloud of very tiny microclusters burning intensity. Consequently, for unity Lewis

Engineering Research 45 1990
number flames, increases in the flow velocity convection is studied by solidifying at one tube

tend to inhibit tip opening because of the wall while rotating the other wall. In addition, the

corresponding decrease in the radius of the effects of convection are studied under

flame tip. Experimental results agree with the conditions for which the inner cylinder is removed

theoretical prediction, and further show that tip and solidification is induced at a stationary or

opening is possible by using a sub-unity Lewis rotating end wall.

number fuel stream of hydrogen and carbon

dioxide. A primary objective of the work is to develop and

validate a novel model for predicting the effects

In the third project, a chemical kinetic criterion of of convection on solidification in binary mixtures.

flammability limits is proposed. The criterion is Treating solid, mushy and liquid regions as a

based on defining a flammability exponent, which single continuous domain, the model applied

measures the sensitivity of a crucial termination continuum theory to solidification in mixtures with

reaction to the corresponding branching reaction, convection. Working with two dimensional

and identifying the flammability limit as the state numerical solutions, calculations will be

at which this exponent becomes unity. performed to determine phase front development

Application of this criterion to the carbon- and related velocity, temperature and

hydrogen-oxygen system shows extremely close concentration fields over a wide range of

agreement with the experimental data, for both operating conditions. Predictions will be

the lean and rich limits. The study further shows validated through comparison with experimental

that the H + 02 ---- > 0 + OH is the dominant results obtained for transparent binary mixtures.

branching reaction for all lean and rich limits, that The experiments will involve visual

H + 02 + M ---- > HO2 + M is the dominant determinations of phase front development and

termination reaction for all lean limits, and that flow within the melt, as well as temperature and

the dominant termination reaction for rich limits concentration measurements. The results are

can be mixture specific. expected to provide important insights

concerning the effects of convection on

solidification phenomena such as

Purdue University macrosegregation, while validation of the model

School of Mechanical Engineering $86,196 should provide a useful computational tool for

West Lafayette, IN 47907 01-C industrial processes involving the casting of

90_3 binary materials.

Effect of Forced and Natural Convection on

Solidification of Binary Mixtures

F.P. Incropera Purdue University

This study deals with the influence of combined School of Nuclear Engineering $100000

convection mechanisms on the solidification of est afayette, IN 47907 01-C

binary mixtures in both rectangular and 90-3

cylindrical geometries. The mechanisms include Interfacal Area and nteraca Transfer

natural convection driven by temperature and Two-Phase Flow

solute concentration gradients, as well as forced M. Ish1

convection due to an externally imposed flow or

a rotating surface. In the rectangular geometry, The objective of the research program is to

solidification is induced at one or both of develop instrumentation methods, experimental

opposing planar walls, with the ends capped, data base and analysis leading to predictive

allowing for natural convection, or open, allowing models for describing the interfacial structure and

for passage of an imposed flow and therefore behaviors of two-phase flows. In terms of the

combined convection. For the cylindrical flow structure, the local void fraction, interfacial

geometry, solidification is induced in the annular area concentration, fluid particle size distribution

cavity between cooled inn and/or outical and fow patte inner two-phase flow

walls, and the ends are capped. Combined systems are studied in detail. For the purpose of

understanding the dynamic behaviors, the

Engineering Research 46 1990
interfacial velocity, wave characteristics and than reported in any study to date. The wall

coalescence and disintegration of fluid particles temperature characteristics, usually presented

are investigated. Special emphasis is placed on as a boiling curve, are unknown at such high

developing the four-sensor and five-sensor heat fluxes.

resistivity probe method and improving the

double-sensor resistivity probe method. A An experimental program has been designed

second emphasis is on the system size and to systematically investigate the effects of

entrance effects on the interfacial characteristics subcooling velocity, tube geometry, and

described above. The changes in the interfacial enhancement techniques on CHF, the boiling

structures and flow regimes as a function of an curve, and the pressure drop. The CHF's will

axial location are measured experimentally. This be correlated as a function of flow and

information together with the local measurements geometrical variables. The experiments will be

from the probe method are used to study the complemented by mechanistically based

mechanisms of flow regime transitions. This .models for CHF under normal and enhanced

research is part of a joint program between the conditions.

University of Wisconsin-Milwaukee

(Kocamustafaogullari) and Purdue. The research The experimental facility has been modified to

program is expected to lead to a) local permit data acquisition under extreme

instrumentation methods for detailed interfacial conditions of flow and heat flux. CHF data

characteristics, b) data for local interfacial area, have been obtained with pure water flowing in

void fraction, relative velocity and wave plain tubes to describe the main parametric

propagation velocity, and c) phenomenological trends. A complementary data base of results

models for interfacial area and interfacial from the literature is being assembled for the

structural changes. correlation development.

Rensselaer Polytechnic Rensselaer Polytechnic

Institute Institute

Department of Mechanical Engineering, $ 0 Dept of Mechanical Engineering, $122,541

Aeronautical Engineering & MechanicsOl-B Aeronautical Eng & Mechanics 01-A

Troy, NY 12180-3590 89-4 Troy, NY 12180-3590 88-3

Ultimate Limits of Boiling Heat Fluxes Inelastic Deformation and Damage at High

A.F. Bergles, M.K. Jensen Temperature

E. Krempl

This study is directed toward the

thermal-hydraulic behavior of water and A combined theoretical and experimental

aqueous mixtures, flowing in plain tubes and in investigation is performed to study the biaxial

tubes with enhancement devices, at very high deformation and failure behavior of AISI Type

heat fluxes. The mode of heat transfer is 304 Stainless Steel under low-cycle fatigue

subcooled nucleate boiling, and the limiting conditions at elevated temperature. The purpose

phenomenon is the critical heat flux (CHF). is to characterize the material behavior in

Very large heat fluxes can be accommodated mathematical equations which are ultimately

on a steady basis with pure water by use of intended for use in inelastic stress analysis and

large subcoolings, high velocities, small tube life prediction. Creep-fatigue interaction and

diameters, and short tubes. It is expected that ratchetting are of special concern. The

simultaneous use of several enhancement long-term goal is the development of a finite

techniques will extend the maximum heat flux element program that can directly calculate the

to at least 5x1 0 W/m2, which would be higher life-to-crack initiation of a component under a

given load history.

Engineering Research 47 1990
For the experiments, an MTS servohydraulic phenomena are also being investigated, both

axial/torsion test system is available together with analytically and experimentally, in order to

an MTS Data/Control Processor. Induction assess and thoroughly understand the effect of

heating (10 kHz) frequency), MTS biaxial grips the proposed closure laws on the void wave

anid an MTS biaxial extensometer are available eigenvalues of the two-fluid model (i.e., to study

together with a reversing direct current potential well-posedness).

drop facility. It is intended for early monitoring of

damage during cyclic loading. It has been tested It is intended that the results of this research will

out at room temperature. significantly advance the state-of-the-art in the

two-fluid modeling of two-phase flows such that,

Uniaxial and torsional ratchetting experiments in the future, multidimensional two-fluid models

showed considerable strain accumulation at room can be used with confidence for many problems

temperature and they demonstrate that of practical interest.

ratchettirng ' is due to viscous effects.

Surprisingly,' insignificant ratchetting and rate

sensitivity were observed at 550, 600 and 650°C Rensselaer Polytechnic for uniaxial tests. This unexpected finding was Institute

attributed to'strain aging in the stainless steel. A IlS U

finite deformation theory of viscoplasticity based Dept of Chemical Engineering $80,495

on overstress (VBO) is being developed and is Troy, NY 12180-3590 01-C

being implemented into a finite element computer 89-3

program. To simulate the complex hardening Microcomputer Enhanced Optical

behavior of AiSI Type'304 Stainless Steel during Investigation of Spreading and Evaporation

non-propotional !oading, new hardening rules Processes in Ultra-Thin Films

are under' investigation and are being P.C. Wyner, Jr.

implemented into the small deformation VBO

theory deve!oped previously. The physicochemical phenomena associated with

fluid flow and change-of-phase heat transfer in

ultra-thin (thickness less than 10-5 m) liquid films

will be studied. During the first year microscopic

Rensselaer Polytechnic image-processing equipment, procedures, and

Instit te' related computer programs will be developed to

Deatetnsofuee -117428 improve data resolution and automate data Department of Nuclear Engineering $117,428 acquisition. First, the image processing First, the image and Engineering Physics 01-C equipment will be developed and used in

Troy, NY 12180-3590 89-4 conjunction with an interferometer designed to

study the transient film thickness in draining films

The Continuum Modeling ~of Two-Phase in an inclined cell. The glass cell will be

Systems designed to optimize temperature control,

R.T. Lahey, Jr., D.A Drew cleanliness and simplicity. The optical data will

be obtained using a video camera attached to a The primary objective of the research being microscope through which the interference

conducted is .to develop a mathematically fringes will be recorded. Transport processes in

consistent multidimensional two-fluid model polar and non-polar fluids, with and without heat which agrees with data and satisfies all the transfer, will be experimentally studied and

constraints implied by physical laws and the analyzed. Using the results of these studies, an

postulates of continuum mechanics. ellipsometer with a complementary interferometer

will be designed for construction and use in

To interfacial this end, closure laws subsequent years. The long term objective is to developed such that two-fluid models can be determine the heat transfer characteristics of

used to predict many important phenomena, evaporating ultra-thin liquid films. The near term

such as the evolution of interfacial area density objective is to develop microscopic

and flow regime transition. Void wave

Engineering Research 48 1990
image-processing equipment and a University of Rochester

complementary heat transfer cell. Dept of Physics and Astronomy $86,218

Rochester, NY 14627 06-C

90-3 University of Rochester Coherence Effects In Radiative Energy

Dept of Physics and Astronomy $63,594 Transfer

Rochester, NY 14627 06-C E. Wolf

89-3

Flux Flow, Pinning, and Resistive Behavior The conventional approach to radiative transfer

In Superconducting Networks rests on the premise that geometrical optics is a

S. Teltel valid approximation to the exact solutions of the

wave equations arising in electromagnetic theory.

The motion of vortex structures, in response to While that may be a correct assumption in the

applied currents, is a major source of resistance case of propagation in homogeneous media, it

in superconducting networks in magnetic fields. may not be so in the case of random media with

Systems of interest include regular Josephson relatively short correlation lengths. For in that

junction arrays and type II superconductors, such instance account must be taken of the coherence

as the new granular high Tc ceramics. properties of the propagated radiation, an aspect

Numerical simulations of finite temperature, of optics outside of geometrical optics.

current carrying, networks will be carried out to

provide a characterization of vortex response in The proposed research will examine the limits of

non-equilibrium situations. For periodic validity of the theory of radiative transfer and

networks, current-voltage (I-V) characteristics radiometry. At the same time the degree to

will be computed and compared with which coherence affects energy distribution in a

experimental results. The effects on resistivity of source will be examined.

transitions from pinned to unpinned or to melted

vortex structures, will be investigated. - For More specifically, some problems with known

disordered networks, the effects of pinning in solutions obtained by conventional means will be

producing metastable vortex structures leading to reexamined from the point of view of coherence

glassy behavior will be explored. theory. Here the effects. of randomness of the

medium in which the propagation takes place will

To date, simulations have been carried out for be taken into account explicitly. It is expected

two dimensional regular Josephson junction that this exercise will clarify the conditions under

arrays with various values of applied magnetic which the conventional radiative transfer

field. I-V characteristics and resistivity were approach must be replaced by coherence theory.

computed and related to vortex structure.

Preliminary work on the behavior of flux line Further, the trade-offs between coherence and

lattices in three dimensional networks has begun. intensity distribution at a radiation source will be

examined with a view to determining the resulting

This research will greatly enhance our effects on radiance distribution in the far field.

fundamental understanding of pinning and flux Recent theoretical results confirmed by

flow resistance in superconducting materials, experiments suggest that such effects may lead

The results will have impact in understanding the to the design of more energy-efficient sources of

magnetic properties of the new high Tc electromagnetic radiation, for instance for

superconductors, and in the design of Josephson illumination purposes.

junction arrays for use as microwave

detectors/generators.

Engineering Research 49 1990
Finally, the effects of the interplay between the Sandia National Lab

statistical properties of the incident light and the Fluid, Thermal, and $29,580

statistical properties of the scattering medium will Structural Sciences Division 03-B

be examined.. Recent novel and unexpected Albuquerque, NM 87185 89-1

results show that under some conditions such

interactions may lead to a shift in the spectrum of. Two-Phase Flow Measurements by NMR

the observed light. R. Gvler R. Givler

We will use nuclear magnetic resonance (NMR) The Rockefeller University to study two-phase flows in model systems.

Department of Physics $78,032 Lovelace Medical Foundation (LMF) will carry out

1230 York Avenue 06-C the experiments while Sandia National

New York, NY 10021 88-3 Laboratories (SNL) will provide the theoretical

'-"~~~ ' "'?"~ ~models of multiphase flows as well as help in

Some Basic Research Problems Related to running the labor-intensive NMR experiments.

Energy' We will study steadily flowing nondilute solid

E.G.D. Cohen suspensions by NMR to obtain the spatial

distributions of the phases as well as the velocity

The present project* is concerned with the distributions of each phase. Such determinations

following problems. 1) The approach to thermal work best under moderately high concentrations

equilibrium of dynamical systems with relatively of both phases, a case that is difficult for light

few degrees-df-freedom is studied. This is of and ultrasound scattering. Our exploratory

interest not only for the foundations of statistical studies for the coming year will include the

mechanics but also for chemical and other following: 1) flow studies of suspensions (heavy

problems. The question is: when does particles in a Newtonian oil) in horizontal tubes to

equipartition of energy and other thermal determine the dependence of flow properties on

equilibrium properties hold? Computer aswell particle diameter, particle diameter to tube

as theoretical calculations will be used. 2) An diameter ratio, mean particle concentration,

investigation of Lorentz lattice gas cellular particle shape and surface roughness, mean flow

automata with independent particles moving on rate, and relative phase densities; 2)

a lattice occupied by randomly placed scatterers measurement of the velocity and spatial

is carried out. Two goals are a closer study of distribution of a water/oil mixture in the annular

(a) the abnormal diffusion found in strictly region between counter-rotating,

deterministic models and, (b) the connection with eccentrically-nested cylinders, and 3)

polymer statistics. Computer and analytic measurement of the simultaneous,

approaches will be employed. This investigation time-averaged, axial velocity profiles for two

is also expected to elucidate the connection immiscible liquids such as oil and water flowing

between particle motion in lattice gas cellular in a horizontal tube.

automata and the hydrodynamic behavior of

fluids in general.. 3) A possible relation between

the transport coefficients of a fluid in ordinary

space and the Lyapunov exponents of the same

system in phase space will be investigated using

computer simulations as well as theory. 4) A

newly discovered analogy between the structural

relaxation found in dense atomic fluids and that

in concentrated solloidal suspensions will be

further explored. Laboratory experiments,

computer simulations as well as analytical

methods will be used.

Engineering Research 50 1990
Sandia National Laboratories breakup of liquid ligamentsand large droplets. In

Combustion Research Facility $138,040 particular, finite-volume computations will be

Thermoflulds Division 06-B used to study the time :evolution of surface

Uvermore, CA 94550 90-3 disturbances on a three-dimensional liquid

element as it deforms and breaks up under the

Mixing and Phase Change During influences of variable-property interfacial tension,

Combustion aerodynamic forces, liquid circulation, heat

AR. Kerstein transfer between phases, and vaporization. Since the three-dimensional analysis provides all

The principal focus of this research program is surface force components, the drag coefficient

the development of a turbulent mixing model will also be characterzed for a family of

applicable to combustion flows. In work to date, non-axisymmetric liquid elements as they

a novel computational' approach has been experience the highly nonlinear transport

formulated in which turbulent stirring is processes mentioned above. The scope of this

represented by non-linear mappings on a line, research proposal is limited to computational

iterated according to a stochastic rule that studies, however this research is closely tied to

incorporates key aspects of the Kolmogorov experimental research efforts at Sandia and

cascade picture of turbulence. Computations elsewhere. Two spray combustion experiments

and analysis demonstrate substationally better are beginning at Sandia's Combustion Research

predictive capability than achieved by previous Facility, one with a pulsed spray and one with a

models of molecular mixing in turbulent flow. steady spray. Data from these experiments will

Future work will involve further analysis of the aid in verification of breakup criteria predicted by

mathematical origins of the computed results, the model under development.

refinement of the model to capture subtle effects

such as the influence of molecular diffusion on

turbulent transport, and application to unsolved Stanford University

problems of turbulent mixing in non-reacting Dept of Mechanical Engineering $160,000

turbulent shear flows and turbulent combusting Stanford, CA 94305-3030 01-B

flows. 89-3

Heat Transfer in Three-Dimensional

Aspects of heterogeneous combustion are also Turbulent Boundary Layers

addressed in this program. Stochastic network- J. Eaton

breakup models are applied, on a macroscopic

scale, to the morphological evolution of a The objectives of this research are to identify,

reacting porous solid, and on a microscopic understand, and model the effects .of three

scale, to the thermochemical dissociation of a dimensionality on turbulent boundary layer heat

macromolecular fuel such as coal. transfer. Early work on this project

examineddistortions of a 2D boundary layer with

embedded longitudinal vortices. Experiments

Sandia National Laboratories showed that two-dimensional similarity laws are

Combustion Research Facility $138,040 violated and that new modelling concepts are

Thermofluids Division 06-B needed to correctly represent embedded vortex

Livermore, CA 94551-0969 87-3 flows. The next set of experiments examined an

initially 2D boundary layer which was skewed

Nonlinear Analysis of Ligament and Droplet laterally resulting in.strong three dimensionality.

Breakup Rapid distortion of the turbulence structure was

B.R. Sanders, H.A Dwyer, D.S. Dandy observed but this apparently had a~mirior effect

on the heat transfer behavior. A vector enthalpy

The objective of this research program is to thickness was defined which extends standard

study the nonlinear fluid dynamics and transport correlations to this new area.

processes which govern the deformation and

Engineering Research 51 1990
Two experiments are presently ongoing. The algorithms for determining the limiting speed

first examines the interaction of an embedded which defines the first transonic state. In the

longitudinal vortex with a three-dimensional coming year we intend to improve these graphics

boundary layer. The results were surprising in capabilities to include rotations and slicing, and

that the vortex was attenuated about one order to extend our elastic studies to deduce the

of magnitude more rapidly in a 3D boundary behavior at interfacial crack tip singularities in

layer than in a similar 2D layer. The boundary anisotropic elastic and piezoelectric media.

layer distortion is strongly dependent on the sign

of the vortex. These results appear to have Problems of composite materials consisting of

considerable significance to flow control single inclusions or two inclusions have been

applications of vortex generators. The second solved using a 'circle theorem' developed

experiment is being developed to study the previously and a two-circle theorem" discovered

three-dimensional boundary layer on a rotating in the past year. The latter theorem is now

disk at a tip Reynolds number of approximately being used to study inclusions with either bonded

1 million. The disk apparatus is complete and a or 'slipping' interfaces. Using Noether's

new laser Doppler anemometer is being installed. theorem, conservation laws based on

A heat transfer measurement disk is also being non-classical transformations are being

developed., examined for their application to fracture and

defect mechanics. Finally, our previous work on

isothermal thermodynamics of stressed solids as

Stanford University applied to theories of damage in brittle solids is

Dept of Mechanical Engineering $161,000 being extended to non-isothermal conditions.

Stanford, CA 94305-3030 01-A

86-4

Energy Changes in Transforming Solids Stanford University

G. Herrmann, D.M. Barnett W.W. Hansen Lab of Physics $252,549

Stanford, CA 94305-3030 03-B

The objective of. this research is to investigate 90-3

problems of stressed deformable solids in which Nondestructive Testing

computations of energy changes and associated G.S. Kino

thermodynamic (or configurational) forces have

important implications. The object of this research is to determine the

usefulness of new optical methods, including

During the past year we have developed a photoacoustic and photothermal measurements

computational routine capable of computing the as novel techniques in solidstate research,

energies of, and forces on dislocations in layered notably for high critical temperature

anisotropic media, which are important superconductivity.

configurations of interest in modem integrated

circuit technology. The theory of interfacial The proposed research deals with the

(Stoneley) waves in bonded piezoelectric development of nondestructive techniques for

half-spaces has been fully developed, as has characterizing the new high temperature

also the theory and computations of so-called superconducting materials. Those materials are

zero curative extraordinary transonic states in difficult to characterize because they are

anisotropic elastic media. Orientations and polycrystalline, brittle, highly anisotropic, and

elastic constant restriction admitting Type 3 inhomogeneous. The noncontacting

transonic states have been delineated for five of photoacoustic and photothermal techniques

the eight anisotropic crystal classes. Color developed in the preceding phase of this project

computer graphics is now being used to produce can provide important information on the nature

three-dimensional views of slowness surfaces in of the microstructure and grain boundaries which

anisotropic elastic and piezoelectric solids; this influence the superconducting. properties.

work has also led to the production of faster

Engineering Research 52 1990
Stanford University Adaptive gridding allows the grid to be selectively

Department of Civil Engineering $98,497 refined only in those areas where high resolution

Environmental Fluid Mechanics Lab 01-B is required, thus facilitating large savings in both

Stanford, CA 94305-4020 90-3 computational time and memory requirements.

Fluid Mechanics of Double Diffusive :;

Systems Stanford University

J.R. Koseff, R.L Street, S.G. Schladow High Temperature Gasdynamics $198,870

Stanford, CA 94305 03-B

This project is focused on processes that occur 88-4

in a double-diffusive system subject to external Diagnostics for Plasma Chemistry

forcing, using a combined experimental and C.H. Kruger, M.A. Cappell

numerical approach. In particular it addresses a

water body that is continuously stratified in both This research is concerned with optical

temperature and salinity. The forcing is provided diagnostics for plasma chemistry and plasma

by a combination of a lateral heat flux and a processing, with an emphasis on methods which

surface shear. Double-diffusive instabilities and allow for departures from local thermodynamic

mixed layer deepening occurs in response to this equilibrium -- such as finite chemical reaction

forcing, resulting in changes to the vertical and rates, nonequilibrium electron densities and

horizontal fluxes of heat and salt. The goals are temperatures, and radiation loss effects. Laser

to (1) understand the initiation and evolution of and other optically based methods are being

the double diffusive instabilities, (2) quantify the developed for measurements of plasma

effects on the vertical fluxes, and (3) compare parameters including electron density and

observations of the mixed layer deepening to the temperature. The methods under study are

existing data for singly stratified systems. The designed to be applicable whether or. not the

experimental component has to date plasma is in local thermodynamic equilibrium,

concentrated on the effects of lateral heating. A and indeed to assess the importance of

new 4.0 m long and 0.8 m wide experimental nonequilibrium effects under conditions of

tank, together with appurtenant facilities for interest in plasma chemistry.

controlling the initial stratification, has been Results with an induction plasma facility show

commissioned. The end wall of this tank is significant nonequilibrium at the exit of a

uniformly heated using a radiant source. Fast downstream quartz test section and suggest

response thermistor and conductivity probes are possible errors in conventional diagnostics

used to provide vertical profiles, and flow assuming local thermodynamic equilibrium.

visualization is provided by video imaging of dye Measurements of the radiation source strength in

in illuminated planes. Initial findings suggest that argon indicate an order-of-magnitude difference

the nature of resulting convective intrusions is a from values reported earlier at temperatures of

function of two dimensionless stability interest in plasma processing. . parameters. The numerical component involves

using a finite volume formulation of the To apply this approach to diagnostics to a

non-linear Navier-Stokes, conservation of mass, realistic and promising form of plasma

and conservation of species equations in three processing, we have undertaken experiments on

space dimensions and in time. The experimental diamond synthesis on substrates in the test

results suggest that the high resolution required section of the induction torch. Diamond crystals

to satisfactorily represent the intrusion interfaces and films have been grown at rates that are at

will make a conventional modeling approach very least one order of magnitude greater than those

difficult, with the number of grid points required characteristic of low-pressure diamond

to resolve the interfaces excessive, even in the synthesis.

context of modern supercomputers. For this

reason work on implementing an adaptive

gridding procedure has been commenced.

Engineering Research 53 1990
Stanford University component shaping. Better analysis,

Department of Chemistry $ o approximation and computation methods would

Stanford, CA 94305 06-C contribute to the design of lower weight, more

89-3 energy efficient vehicles and machines. Since

Reduction of Dissipation in Combustion and for existing methods each iteration requires a

Engines computationally intensive finite element analysis

J. Ross (FEA), these innovations are intended to reduce

the number of FEA iterations.

Research is concerned with the issue of the

enhancement of power output in thermal and This approach has been applied successfully to

chemical engines by means of external the shaping of a planar cantilever support for

perturbations of constraints coupled to minimum weight. Three zones: (1) the fillet near

nonlinearities of the mechanism of the engine. the support, (2) an interior zone free of stress

The theoretical possibility of an increase in power concentration, and (3) one near the load -- were

output of a thermal engine driven by a chemical modeled approximately by classical solid

reaction by means of external periodic variations mechanics and more precisely by FEA.

of reactant influx has been confirmed in a series Monotoncity analysis of the classical

of experiments. The power output of an engine approximation identified as critical the shear

is necessarily accompanied by dissipation due to stress near the load and the bending stress in

irreversible processes essential for. power the fillet and interior zones. This immediately

production. Hence an increase in power output determined the optimal shape of the interior and

by means of external perturbations usually load zones. It also gave the differential equation

implies a decrease in dissipation but may also of the fillet shape as a function of its variable

come about due to a change in the final state of curvature, initially unknown. FEA-predicted

the Increases system. in efficiency can be deviations of fillet stress from the desired value

achieved for a 'particular range of frequencies generated a new curvature function whose

and amplitudes of external perturbations which integration produced a much better shape. Only

yield resonance effects and appropriate phase three iterations were needed for convergence.

shifts of fluxes and forces. Theoretical and The idea is also proving practical for deflectionexperimental studies are in progress on and vibration-limited cantilever situations. A

optimization of efficiency by choices of functional connecting rod vibration study has shown

forms of external perturbations. A variational remarkably large shape improvement in a single

theory has been constructed which gives limits of iteration.

improvements in efficiency by external

perturbations.

Stevens Institute Of

Technology Stanford University Dept of Physics and Engineering $64,077

Dept of Mechanical Engineering $80,218 Hoboken, NJ 07030 06-C

Design Division 03-A 87-4

Stanford, CA 94305 88-3 Investigation of Transitions From Order to

Chaos in Dynamical Systems

Monotonicity Analysis and Geometric G. Schmidt

Programming in Mechanical Shape

Optimization The transition from order to chaos in dynamical

D.J. Wilde, S.D. Sheppard systems of few degrees of freedom are studied,

using theory, numerical computation and a

This theoretical and computational research laboratory experiment as tools of this

intends to bring the theory and practice of investigation. This work is nearly completed and

Monotonicity Analysis and Geometric we are tooling up to study more complex

Programming to bear on finite element systems with many degrees of freedom.

optimization problems related to mechanical

Engineering Research 54 1990
We have determined the dynamics of transition Ensemble-averaged equations for the

from Hamiltonian to dissipative systems in the propagation of pressure waves in bubbly liquids

chaotic regime. As the Hamiltonian limit is have been derived correct to second order in the

approached, strange attractors disappear in an gas. volume fraction. A new insight into the

orderly fashion as dissipation is reduced. There structure of the expansion and the role of

exist a set of universal Jacobians Jn' where the bubble-bubble interaction and surface

2n piece strange attractors disappear. This deformations is obtained from the work.

phenomenon is universal as we have proven

using renormalization calculations, in the vicinity In a second study, by arranging N bubbles at

of the universal Hamiltonian function T*. In fact random in a cubic cell and filling up the entire

we have shown that all phenomena possess a space with copies of this cell, the behavior of an

universal scaling in the K-J parameter space, infinite bubbly liquid has been simulated. For

where K is the strength parameter and J is the this situation two alternative definitions of added

Jacobian. mass have been explored and the average

viscous dissipation in the limit of large Reynolds

We studied universal strange attractors, number has been studied.

homoclinic and heteroclinic crises, Uapunov

exponents and windows. Everything scales In another study, the propagation of pressure

along fan lines in parameter space in a well waves in a layer of bubbles has been

defined manner. considered. The novel feature of this work is the

fact that the volume fraction is arbitrary and the

Physical systems that produce two dimensional wavelength can be comparable to the intermaps are of course different from the universal bubble distance. The last problem involves the

ones. We have found recently that such systems flow of a "plug" of bubbly liquid in a conduit. For

exhibit extremely rapid convergence to the the time being the bubbles are arranged on the

universal sequence of Jn values. Among the axis of the conduit, but will later be placed at

systems studied were the driven damped random.

pendulum, the bouncing ball, and the particle in

the -standing wave field. All systems studied

exhibited the rapid convergence to the universal University Of Texas At Austin

system as predicted. The fundamental theory of Ctr for Studies in Statistical Mech $94,700

dissipative dynamical systems, represented by Austin, TX 78712 06-C

two dimensional maps has been established. 88-3

The Behavior of Matter Under

Nonequilibrium Conditions: Fundamental Syracuse University Aspects and Application in

Dept of Mechanical Engineering $57,572 Energy-Oriented Problems

and Material Sciences 01-C I Prigogine

Syracuse, NY 13244 90-2

This research aims at new fundamental

Numerical and Physical Modeling of Bubbly developments in the area of non-equilibrium

Flow Phenomena phenomena, as well as at various applications to

A Sangani disciplines in which complex systems giving rise

to instabilities and bifurcations are of current and

The ultimate purpose of this study is to put the primary concern. Special emphasis is being

widely used engineering averaged-equations placed on three principal directions: 1)

models of multi-phase flows on a firmer footing Continuation of the study of self-organization on

by comparing their results with those of direct the microscopic scale, as exemplified in the early

numerical multi-particle simulations and stages of matter-radiation interaction. 2)

rigorously-derived averaged equations. Investigation of the onset of coherent temporal

behavior and spatial pattern formation at the

microscopic level, by means of molecular

Engineering Research 55 1990
dynamics: a) Approach to equilibrium starting theoretic property, the mutual information, is

from initial nonequilibrium spatial distributions. being examined as a means for detecting and

Preliminary results show that equilibrium quantifying spatiotemporal chaos. The work has

structures are produced by nonequilibrium demonstrated that information on 'dynamics

processes, involving long-range and long-living deduced from noisy data can be used to reduce

correlations. b) Observation of sustained stable the noise in those data. These tools from

rhythmic phenomena in a model involving 3 dynamical systems and information'theory' are

chemical intermediates undergoing binary being applied to data obtained in laboratory

collisions. Preliminary results show agreement experiments on homogeneous systems and on

with macroscopic reaction-diffusion theory, for a extended systems. A novel unstirred chemical

homogeneous system. The onset of stable reactor has been designed for studies of the

spatial chemical patterns (Turing instability) is development and evolution of chemical spatial

currently under investigation. The important patterns, and experiments with this reactor have

conclusion is that dissipative structures are the yielded the first sustained chemical spatial

outcome of dynamical processes at the patterns in a controlled laboratory environment.

microscopic theories which are based on These laboratory experiments and numerical and

phenomenological assumptions. 3) Molecular analytic studies of models should provide general

dynamics computer experiments testing the limits insights into spatiotemporal ' patterns in

of validity of macroscopics physics: The nonequilibrium systems.

traditional formulation of macroscopic physics ,-

rests on the strict applicability of the local

equilibrium assumption. Most of the familiar Tufts University phenomena of non-linear physics, such as Dept of Mechanical Engineering $53,978

hydrodynamical and chemical -instabilities, Medford MA 02155 01-A

turbulence, combustion etc. are direct 88-3

manifestations of this hypothesis. For Effective Elastic Properties of Cracked Solids

gas-phase exothermal chemical reactions, Kachanov

significant deviations from the usual equilibrium

theory have recently been measured through The knowledge of effective elastic properties of

molecular dynamics. The origin of these solids with cracks appears to be of increasing deviations can be explained by the perturbation engineering importance. Extensive

of the local Maxwellian distribution through microcracking in structural elements working

reactive collisions. Quantitative agreement with under conditions of high temperaures or

a theory taking account of this effect have been irradiation, and microcracking in composite

established. materials under fatigue conditions may noticeably

reduce the stiffness of the material and make it

anisotropic. Understanding and /prediction of

University Of Texas At Austin these changes are essential for proper design

Department of Physics $139,209 and strength and lifetime assessments. A new

Austin, TX 78712 06-C approach to'many cracks problems. based on

87-5 interrelating the average tractions on individual

Complex Temporal and Spatial Patterns in cracks is introduced.. Its advantages are that it

Nonequilibrium Systems yields simple analytical results which are. quite

H.L Swinney accurate up to very high crack densities and that

it can be applied to crack.. arrays or arbitrary

Dynamical systems methods are being geometry. Relation between deterioration of

developed and used to characterize elastic properties and "damage"'is discussed.

nonequilibrium processes and to address

outstanding unresolved questions regarding

bifurcations and chaos, especially in

reaction-diffusion systems. An informationEngineering Research 56 . 1990
United Technologies Research Washington University

Center Department of Systems Science $69,957

Propulsion Science Laboratory $175,217 and Mathematics 03-A

East Hartford, CT 06108 06-A Saint Louis, MO 63130 90-3

89-3

Laser Diagnostics Of PACVD Processes Dynamical Systems with Internal Structure:

W.C. Roman, S.O. Hay, FA. Otter, A New Approach to the Problem of Analysis

AC. Eckbreth and Robust Design of a Time Varying System

The objectives of this research are to perform a B. Ghosh

comprehensive experimental investigation of the

fundamental nonequilibrium reactive plasma The main objective of the proposed project is to

assisted chemical vapor deposition (PACVD) study design problems for linear time-varying

process applicable to hard face coatings. Based control systems leading to a robust design via an

on its superior erosion resistance, TiB2 was adaptive controller. Specifically, for

selected as the initial coating for deposition onto autoregressive moving average systems with

a titanium alloy substrate (Ti-6A1-4V). In task time-varying coefficients, it turns out that agood

I, novel non-intrusive laser diagnostic techniques design strategy is to adaptively assign the

(e.g. Laser Induced Fluorescence Spectroscopy parameters of the closed loop system by a

(LIFS), and Coherent Anti-Stokes Raman judicious choice of a time-varying compensator.

Spectroscopy (CARS)) are being used to The parameters of the compensator which assign

determine, in situ, the reactive plasma a specified set of coefficients in the closed loop

composition, temperature, and species satisfy a nonlinear recursion. We propose to

concentration and distribution in the gas phase. study these recursions in details. For specific

Coupled with these experiments will be modeling cases, we show that the proposed recursion is

of the plasma chemistry process. The second an Anosov differmorphism on a threetask includes use of Auger Electron dimensional torus. In particular, such a dynamic

Spectroscopy (AES), Ion Scattering is chaotic. We feel that our design should try to

Spectroscopy (ISS), Secondary Ion Mass avoid chaotic dynamics.

Spectroscopy (SIMS) and other complementary

techniques for detailed coating characterization. In order to analyze and design a compensator

These are being combined with physical for a time-varying system it is-important to be

measurements of coating surface smoothness, able to estimate the trend, i.e., predict future

hardness (state-of-the-art nanoindenter values of the parameters of the system. An

apparatus) and adherence (UTRC custom built important part of our project is to assume that

pin-on-disc apparatus). These combined tasks the parameters change in accordance with an

will allow a correlation of the PACVD parameters internal structure viz a time series. Our goal is to

with their required coating properties, thus estimate the parameters of the internal structure.

providing a predictive capability that is severely

lacking in the present science base of advanced Thus we propose to investigate in this project an

protective coatings. Results to date include: 1) identification scheme with internal structure

fabrication of a 5 kW rf PACVD reactor system together with recursive coefficient assignment in

integrated with a completely oil-free, high real time in order to generate a desirable

vacuum system; 2) exploratory spectral emission performance in the closed loop.

surveys for major molecular band and atomic line

identification; 3) development of a colinear,

scanned, narrowband CARS system; 4)

implementation of a ultramicrohardness tester

and adhesion test apparatus; 5) initial

characterization of TiB2 and diamond coatings;

and 6) first time CARS measurement of several

key species (e.g. B2H6).

Engineering Research 57 1990
Washington State University University Of Wisconsin

Dept of Mechanical Engineering $66,290 Mechanical Engineering Department $99i869

Pullman, WA 99164-2920 01-B Madison, WI 53201 01-C

89-2 90-3

Particle Dispersion by Ordered Motion in Interfacial Area and Interfacial Transfer in

Mixing Layers Two-Phase Flow Systems

T.R. Troutt G. Kocamustafaogullarl

The primary. goal of this research is to determine The objective of the research program is to

the role organized vortex motions play in the develop instrumentation methods, experimental

dispersion of particles by free shear flows. This data base and analysis leading to predictive

research goal has been pursued using analytical, models for describing the interfacial structure and

numerical and experimental techniques to behaviors of two-phase flows. In terms of the

examine the particle dispersion process in plane flow structure, the local void fraction, interfacial

mixing layers and wakes. The results of these area concentration, fluid particle size distribution

studies have shown that the character of the and flow patterns in vertical two-phase flow

particle dispersion process in free shear flows is systems are studied in detail. For the purpose of

a function of a time scale parameter formed understanding the dynamic behaviors, the

between the ratio of the particle aerodynamic interfacial velocity, wave characteristics and

response time and the time scale of the coalescence and disintegration of fluid particles

organized vortex motion. For intermediate time are investigated. Special emphasis is placed on

scale ratio particles two types of dispersion developing the four-sensor and five-sensor

mechanisms have been recently identified. In resistivity probe method and improving the

mixing layers, where large scale vortex mergers 'double-sensor resistivity probe method. A

occur regularly, intermediate scale particles are . second emphasis is on the system size and

concentrated into sheet like patterns' which entrance effects onthe interfacial characteristics

undergo stretching and folding operations. For described above. The changes in the interfacial

plane wakes, where large scale vortex mergers structures and flow regimes as a function of an

are not a dominant feature, intermediate scale axial location are measured experimentally. This

particles are "focussed" into highly concentrated information together with the local measurements

regions near the vortex boundaries. The from the probe method are used to study the

resulting order of the self-organized particle mechanisms of flow regime transitions. This

dispersion patterns for both mixing layers and research is part of a joint program between

wakes can be quantified using the fractal Purdue University (Ishii) and the University ofcorrelation dimension. This quantity is found to Wisconsin-Milwaukee. The research program is

be a strong function of particle time scale ratio. expected to lead to a) local instrumentation

Current research efforts are aimed at further methods for detailed interfacial characteristics, b)

exploring these -dispersion mechanisms and data for local interfacial area, void fraction,

developing improved strategies for predicting and relative velocity and wave propagation velocity,

controlling particle dispersion in free shear flows. and c) phenomenological models for interfacial

New design concepts for multiphase mixing area and interfacial structural changes.

systems are a highly plausible application of

these results.

Engineering Research 58 1990
University Of Wisconsin

Dept of Chemical Engineering $104,170

Madison, WI 53706 03-A

89-3

The Development of Process Design and

Control Strategies for Energy Efficiency,

High Product Quality, and Improved

Productivity in the Process Industries

W.H. Ray

The process industries are having great difficulty

competing in the world market because of high

energy costs, high labor rates, and old

technology for many processes. This project is

concerned with the development of process

design and control strategies for improving

energy efficiency, product quality, and

productivity in the process industry. In particular,

(i) the resilient design and control of chemical

reactors, and (ii) the operation of complex

processing systems, will be investigated. Major

emphasis in part (i) will be on two important

classes of chemical reactors: polymerization

processes and packed bed reactors. In part (ii),

the main focus will be on developing process

identification and control procedures which allow

the design of advanced control systems based

on limited process information and which will

work reliably when process parameters change

in an unknown manner. Specific topics to be

studied include new process identification

procedures, nonlinear controller designs,

adaptive control methods, and techniques for

distributed parameter systems. Both

fundamental and immediately applicable results

are expected. The theoretical developments are

being tested experimentally on pilot scale

equipment in the laboratory. These experiments

not only allow improvements in theoretical work,

but also represent real life demonstrations of the

effectiveness of the methods and of the feasibility

of implementing them in an industrial

environment. The new techniques developed in

this project will be incorporated into

computer-aided design packages and

disseminated to industry. Therefore, it is

expected that the work will have an impact on

industrial practice.

Engineering Research 59 1990
Budget Number Index

Mechanical Sciences:

01-A Solid Mechanics: macroscopic aspects of elastic and plastic deformations,

and crack propagation

01-B Heat Transfer

01-C Fluid Mechanics

01-D Tribology

Control Systems and Instrumentation:

03-A Control systems, large scale systems

03-B Instrumentation for hostile environment, and NDE

03-C Intelligent systems

Engineering Data and Analysis:

06-A Thermophysical properties and processes

06-B Combustion

06-C Non-linear dynamics and engineering analysis
Budget Page

Number Number

01-A

Bounds on Dynamic Plastic Deformation .. .... ........... 2

Continuum Damage Mechanics II ........................... .. 2

An Investigation of the Effects of History Dependent Damage in Time Dependent -

Fracture Mechanics .............................. ................ 3

Micromechanical Viscoplastic Stress-Strain Model with Grain Boundary Sliding ... 14

A Micromechanical Viscoplastic Stress-strain Model with Grain Boundary Sliding . . 16

Elastic-Plastic Fracture Analysis Emphasis on Surface Flaws ................. 18

Modeling and Analysis of Surface Cracks .................. ............ 32

Energetics of Comminution .............. .......................... 33

Inelastic Deformation and Damage at High Temperature .................... 47

Energy Changes in Transforming Solids .............................. 52

Effective Elastic Properties of Cracked Solids ........................... 56

01-B

Traveling-Wave Convection in Fluid Mixtures ........................... 9

High Flux Film and Transition Boiling .. ... ..... ..................... 17

Heat Transfer to Aqueous Polymer Solutions . ........................... 22

The Impact of Separated Flow on Heat and Mass Transfer ...... ............. 35

Thinning And Rupture of a Thin Liquid File on a Horizontal Heated Solid Surface . . 41

Ultimate Limits of Boiling Heat Fluxes ................................ 47

Heat Transfer in Three-Dimensional Turbulent Boundary Layers ....... . . 51

Fluid Mechanics of Double Diffusive Systems ........................... 53

Particle Dispersion by Ordered Motion in Mixing Layers ....... ............. 58

01-C

Linear and Nonlinear Stability Topics in Physico-Chemical Hydrodynamics....... 1

Basic Studies of Transport Processes in Porous Media .................... 5

Turbulent Structure in Liquid Streams Bounded by a Free Surface and a Solid Wall . 11

Droplet Motion in Numerically Simulated Turbulence ...................... 13

Experiments in Turbulent Mixing .... ... ............................. 14

Two Phase Potential Flow ...... ... .. .............................. 15

Analytical and Experimental Study of Instabilities in Buoyancy-Driven Convection

in Porous M edia .. ... ...... ............. ... ................. 15

Comparative Study of the Vorticity Field in Turbulent Flows: Theory, Experiments,

Com putations ................ .............. .................. 16

Gas-Liquid Flow in Pipelines ..... .............. ..... .......... 21
OR=C (continued)

Numerical and Physical Modeling of Bubbly Flow Phenomena ................ 23

Turbulence Theory and Reduced Hydrodynamics Description ................. 23

The Use of Stereo Optical Flow Fields in the Determination of Three-Dimensional

Motion and Stereo Correspondence .................................. 25

Comparative Study of the Vorticity Field in Turbulent Flows: Theory, Experiment,

Com putations ................................................. 27

Dryout in Horizontal and Almost Horizontal Heated Tubes .................. 31

Rheological and Flow Characteristics of Dense Multiphase Slurries Employing a

Bimodal Model ............................................... 33

Stability Studies of Core-Annular Flows .............................. 35

Convection and Dispersion in Coarse-Packed Beds ........................ 36

The Rheology of Concentrated Suspensions ................. ........... 37

Comparative Study of Vorticity Field in Turbulent Flows ................... 38

Periodically Structured Multiphase Flows and Hydrodynamic Instabilities

in Narrow Channels ............................................. 38

Attenuation of Waves in Partially Saturated Porous Solids ................... 41

Study of Interfacial Behavior in Cocurrent Gas-Liquid Flows ................. 42

Effect of Forced and Natural Convection on Solidification of Binary Mixtures ..... 46

Interfacial Area and Interfacial Transfer in Two-Phase Flow ................. 46

The Continuum Modeling of Two-Phase Systems ........................ 48

Microcomputer Enhanced Optical Investigation of Spreading and Evaporation

in U ltra-Thin Film s .............................................. 48

Numerical and Physical Modeling of Bubbly Phenomena .................... 55

Interfacial Area and Interfacial Transfer in Two-Phase Flow Systems ........... 58

0[-D

The Development of a Friction Model Predicting the Sliding Behavior of Material

Especially at Low Temperatures ..................................... 32

¢3=A

Integration of Redesign Methodologies for Chemical Processes ................ 11

Intelligent Control of Thermal Processes ............................... 20

Model Building and Control of Large Scale Systems ....................... 21

Screening Alternative Control Structures for Plant Control System ............. 28

Synthesis of Heat and Work Integration Systems for Chemical Process Plants ..... 30

Monotonicity Analysis and Geometric Programming in Mechancial Shape

O ptim ization ................................................. 54

Dynamical Systems with Internal Structure: A New Approach to the Problem of

Analysis and Robust Design of a Time Varying System .................... 57

The Development of Process Design and Control Strategies for Energy Efficiency,

High Product Quality, and Improved Productivity in the Process Industries ....... 59
03-Is

New Ultrasonic Imaging and Measurement Techniques for NDE ............... 1

Nondestructive Evaluation of Superconductors ........................... 20

Two-Phase Flow Measurements by NMR .............................. 25

Pulse Propagation in Inhomogeneous Optical Fibers ....................... 26

Metal Transfer in Gas Metal Arc Welding .............................. 29

Multivariable Control Of The Gas-Metal Arc Welding Process ............... 31

Thermophysical Property Measurements in Fluid Mixtures ................... 36

Effects of Crack Geometry and Near-Crack Material Behavior on Scattering of Ultrasonic Waves for QNDE Applications ........................... 40

Physics of Cellular Automata and Coherence and Chaos in Many-Body

Dynamical Systems .. ........................................... 43

Interaction of Radiation with Surface Microstructure ....................... 44

Nonuniform Liouville Transformers for Quasi-Homogeneous Optical Fields ....... 44

Two-Phase Flow Measurements by NMR .............................. 50

Nondestructive Testing ........................................... 52

Diagnostics For Plasma Chemistry ................................... 53

03-C

Research on a Reconfigurable Modular Manipulator System .................. 12

Neural Learning Formalisms for Global Manipulator Redundancy Resolution

Problems in Unstructured Environments ....... ....................... 22

The Creation of Multi-Degree-of-Freedom Mechanisms for Robotic Applications . . 26

Center for Engineering Systems Advanced Research (CESAR) ................ 42

06-A

Three-Phase System Modelling .............................. 1.... 7. In-Flight Measurement of the Temperature of Small, High Velocity Particles ...... 18 Modeling of Thermal Plasma Processes ................................ 19

Plasma-Particle Interactions ....................................... 19

Design and Synthesis of Reactive Separation Systems ...................... 28

High Temperature Gas-Particle Reactions .............................. 30

Mathematical Modelling of Transport Phenomena in Plasma Studies .......... 34

Transport Properties Of Disordered Porous Media From The Microstructure ....... 40

Bioprocess Engineering Research for Energy Applications ................... 43

Experimental And Theoretical Studies Of Condensation In Multicomponent Systems . 45

Laser Diagnostics Of PACVD Processes ............................... 57
06-B

Studies in the Combustion and Breakup of Transverse Liquid Jets and Fuel Droplets . 6

Fuel Droplets Subject to Straining Flow ............................... 8

Controlled Combustion ....................................... 24

Mechanisms and Enhancements of Flame Stabilization ..................... 45

Mixing and Phase Change During Combustion ........................... 51

Nonlinear Analysis of Ligament and Droplet Breakup ...................... 51

06-C

Transport in Porous/Disordered Materials ............................. 3

Two Studies of Nonlinear Processes in Irreversible Thermodynamics ............ 4

Self-generated Stochastic Heating in an RF Discharge ...................... 4

Modeling of Energy and Particle Transport ............................. 6

Wave Turbulence and Self-Localization in Continuous Media ................. 7

Signal Processing in Chaos ....................... ................ 7

Lattice Gas Simulation of Fluid Flows ................................ 8

The Stochastic Trajectory Analysis Technique (STAT) Applied to Chemical,

Mechanical and Quantum Systems ................................... 9

Bifurcations and Patterns in Nonlinear Systems .......................... 10

Topics in Finite-Time Thermodynamics ............................... 12

Fundamentals and Techniques of Nonimaging Optics for Solar Energy Concentration 13

Studies in Nonlinear Dynamics ..................................... 24

Study of Magnetostatic Problems in Nonlinear Media with Hysteresis .......... 25

Mixing of Viscous Fluids: Behavior of Microstructures and Chaos ............. 29

Macrostatistical Hydrodynamics ........ ............................ 34

Thermal Plasma Processing of Materials ............................... 35

Low Resistivity Ohmic Contacts between Semiconductors and High-Tc

Superconductors ..................... .. .................... ...... 37

Topics in Physico-Chemical Hydrodynamics .......................... 39

Flux Flow, Pinning, and Resistive Behavior in Superconducting Networks ........ 49

Coherence Effects in Radiative Energy Transfer .......................... 49

Some Basic Research Problems Related to Energy ........................ 50

Reduction of Dissipation in Combustion and Engines ...................... 54

Investigation of Transitions From Order to Chaos in Dynamical Systems ......... 54

The Behavior of Matter Under Nonequilibrium Conditions: Fundamental Aspects

and Application in Energy-Oriented Problems ........................... 55

Complex Temporal and Spatial Patterns in Nonequilibrium Systems ............ 56
Principal Investigators

D.I. Abarbanel 7 G. Herrmann 52 D.M. Parks 32

J.D. Achenbach 40 G. Hetsroni 11 C. Peterson 33

G. Ahlers 10 D.K. Hsu 1 E. Pfender 35

G. Andrews 17 A.K.M. Hussain 16 G.C. Pomraning 6

A. Acrivos 37 F.P. Incropera 46 1. Prigogine 55

S. Banerjee 11 M. Ishii 46 R.F. Probstein 33

S.G. Bankoff 41 Y. Iwasa 32 A. Prosperetti 23

J. Barhen 22 J. Jannson 44 S. Putterman 7

D.M. Barnett 52 C. Jayaprakash 43 J.D. Ramshaw 19

T. Basar 21 J.A. Johnson 20 W.H. Ray 59

A.F. Bergles 47 M.C. Jones 36 W.G. Reuter 18

R. S. Berry 12 E.H. Jordan 14 L.D. Reynolds 19

L.T. Biegler 11 D.D. Joseph 35 W.C. Roman 57

P.P. Bolsaitis 30 M. Kachanov 56 J. Ross 54

H. Brenner 34 T. Kanade 12 B.R. Sanders 51

F.W. Brust 3 A.R. Karagozian 6 A. Sangani 55

D.S. Cannell 10 A.N. Kaufman 24 S.G. Schladow 53

M.A. Cappelli 53 R. Kayser 36 G. Schmidt 54

1. Catton 5 A.R. Kerstein 51 C.D. Scott 43

C.H. Chang 19 J. Kestin 4 J.M.H. Sengers 36

E.G.D. Cohen 50 T. Keyes 3 C.B. Shaw 19

D.S. Dandy 51 P.K. Khosla 12 S.D. Sheppard 54

S.H. Davis 41 G.S. Kino 52 G.I. Sivashinsky 39

M.F. Doherty 28 G. Kocamustafaogullari 58 H.B. Smartt 20

J.M. Douglas 28 P. Kokotovic 21 S.C. Snyder 19

D.A. Drew 48 J.R. Koseff 53 R.L. Street 53

J.H. Duncan 25 D. Krajcinovic 2 C.M. Surko 9

H.A. Dwyer 51 E. Krempl 47 H.L. Swinney 56

T.W. Eagar 29 C.H. Kruger 53 J. Szekely 34

J. Eaton 51 R.T. Lahey, Jr. 48 S. Tcitel 49

A.C. Eckbreth 57 C.K. Law 45 K. Telschow 20

T.L. Eddy 19 E. Levich 38 G.L. Thompson 11

J.W. Ekin 37 P.A. Libby 8 D.O. Thompson 1

J.F. Elliot 30 A.J. Lichtenberg 4 S. Torquato 40

J.S. Epstein 18 M.A. Lieberman 4 T.R. Troutt 58

L.B. Evans 30 K. Lindenberg 9 L. Tsai 26

J.R. Fincke 18 R.G. Littlejohn 24 K.P. Walker 16

M.B. Frish 45 W.R. Lloyd 18 J.M. Wallace 27

E. Fukushima 25 C.M. Maldarelli 38 G.B. Wallis 15

J.G. Georgiadis 15 M.F. Malone 28 Z. Warhaft 14

B.K. Ghosh 57 R. Mann 42 P.C. Wayner, Jr. 48

R. Givler 50 I.C. Mayergoyz 25 A.W. Westerberg 11

R.J. Goldstein 35 F.A. McClintock 32 D.J. Wilde 54

A.K. Graham 34 M.J. McCready 42 G. Wilemski 45

P. Griffith 31 J.B. McLaughlin 13 F.A. Williams 8

I.E. Grossmann 11 C. Menyuk 26 R. Winston 13

T.J. Hanratty 21 M.J. Miksis 41 L.C. Witte 17

D.E. Hardt 31 L.A. Mondy 34 E. Wolf 49

J.P. Hartnett 22 J. Moreland 37 J.D. Wolfe 36

B. Hasslacher 8 A.K. Oppenheim 24 C.K. Youngdahl 2

*U.S.G.P.O:1991-281-714:40039
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